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Edited by L. H. Bailet 



MILK AND ITS PRODUCTS 



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MILK AND ITS PRODUCTS 



A TREATISE UPON THE NATURE AND QUALITIES OF 

DAIRY MILK AND THE MANUFACTURE 

OF BUTTER AND CHEESE 



BY V 

- HENRY H. WING 

Assistant Professor of Dairy Husbandry 
IN THE Cornell University 



^\\^-C-\ 



THE MACMILLAN COMPANY 

LONDON: MACMILLAN & CO., Ltd. 
1897 



All rights reserved 



4^ 



Copyright, 1897 
By henry H. wing 



J. Horace McFarland Company 
Harrisburg, Pa. 



r 



Ta mv Father 

AS A SLIGHT TRIBUTE TO THE CAREFUL TRAINING AND 
WISE AND SYMPATHETIC COUNSEL THAT 
SERVED TO INSTIL IN THREE FARM BOYS A LOVE FOR ALL 
THAT PERTAINS TO FARM LIFE 

Ttris little mnvk is affectiotiateljg inscribed 



(v) 



PREFACE. 

The revolution in dairy practice brought about 
•by the introduction of the centrifugal cream sepa- 
ratoi- and the Balu'ock test for fat« and by a more 
definite knowledge regarding the various fermenta- 
tions that so greatly influence milk and the manu- 
facture of its products, has seemed to demand the 
publication of a small handbook that shall give 
to the dairyman, and particularly to the dairy 
student, in simple, concise form, the principles un- 
derlying modern dairy practice. In attempting to 
meet this demand, I have had largely in view the 
needs of my own students, while still keeping in 
mind the general dairy reader. 

In the collation of the information, where so 
many points are still unsettled, it is of course dif- 
ficult in all cases to distinguish fact from conjec- 
ture. The aim has been at all times to give 
the present state of knowledge as supported by 
the weight of evidence and the opinions of those 
whose authority is highest. In how far this has 
been successful time alone can tell. It would be 

(vii) 



viii 'Preface. 

too much to hope that eveiy conchision will stand 
the test of further investigation and experience. 

Dairy practice in the United States owes much 
to the investigations of the Agricultural Experiment 
Stations. Of the results of their labor free use 
has been made in various ways, and in many cases 
without specific mention at the particular place.' 
Without wishing to make distinctions, particular 
acknowledgment is here rendered to the reports 
and bulletins of the Stations in Maine, New Hamp- 
shu-e, Vermont, Connecticut (Storrs), Canada, New 
York (State), New York (Cornell), New Jersey, 
Pennsylvania, Illinois, Iowa, Wisconsin and Minne- 
sota. For those who wish to make more extended 
investigations, a bibliography is added in the Ap- 
pendix, giving references to many bulletins. 

Thanks are due to D. H. Burrell & Co., the 
Vermont Farm Machine Co., the DeLaval Separator 
Co., the Star Milk Cooler Co., the Champion Milk 
Cooler Co., J. F. Hodgkin, and F. B. Fargo & Co., 
for the use of electrotypes. 

Acknowledgment is also due my colleagues, 
Messrs. Cavanaugh, Durand, Hall and VanWagenen, 
for valuable assistance, and to Professor L. H. 
Bailey for much friendly counsel and many useful 
suggestions. 

HENRY H. WING. 

Cornell University Dairy, 
January 1897. 



CONTENTS. 

CHAPTER I. 

Secretion of Milk. 

Milk defined — Mammary glands — Udder — Internal structure of 
udder and teats — Ultimate follicle — Secretion of milk — In- 
centives to secretion — Amount and duration 6i flow — Effect 
of succeeding pregnancy — Incomplete removal of milk — Reg- 
ularity and frequency of milking — Control of animal over 
secretion. 

Pages 1-15 

CHAPTER II. 

Composition of Milk. 

Milk constituents — Colostrum — Specific gravity — The fats — The 
volatile fats — The non-volatile fats — The albuminoids — The 
sugar — The ash — Other constituents — Variations in quality 
of milk. 

Pages 16-32 

CHAPTER III. 

The Testing of Milk. 

Gravimetric analysis — History of milk tests — Cream gauges — 
Specific gravity — Lactometers — Churn tests — Laetobutyro- 
meter — Pioscope — Lactoscope — Soxhlet's method — Laeto- 
erite — Fjord's control apparatus — Milk tests in the United 
States — Short's method — Method of Failyer and Willard — 



X Contents. 

Parsons' method — Iowa Station test — Cochran's method — 
Babeoek test — Beimling test — Gerber's method — Butyrom- 
eter — Details of Babeoek test — The centrifugal machine — 
The glassware — Sampling the milk — Composite sampling — 
Making the test — The acid — Whirling — Reading — Cleaning 
the glassware. 

Pages 33-63 

CHAPTER IV. 

s 
The Ferments and Fermentations of Milk and 

Their Control. 

Tendency to undergo change — Germs of fermentation — Bacteria — 
Presence of bacteria in milk — Kinds of bacteria in milk — 
Fermentations of milk — Relation of milk bacteria to the 
human system — Lactic fermentations — Fermentations affect- 
ing the albuminoids — Butyric fermentations — Control of fer- 
mentations — Prevention of infection — Holding at low tem- 
peratures — Destruction of germs in milk — Pasteurization — 
Selection of milk for pasteurization. 

Pages 64-80 

CHAPTER V. 

Market Milk. 

Milk for consumption — Cleanliness — Treatment after drawing — 
Aeration — Delivery — Quality of milk for consumption — Con- 
trol of milk supply. 

Pages 81-90 

CHAPTER VI . 
Separation of Cream. 

Gravity creaming — Shallow -pan creaming — Deep setting system — 
Centrifugal separation — Conditions affecting completeness of 
separation — Conditions affecting the relative amount of 
skimmed milk and cream — Contrivances in the bowl to 



Contents. xi 

increase the efficiency of separation — Mechanical conditions 
affecting separation — Efficiency of separation in centrif- 
ugal machines — Desirable and undesirable features of a sep- 
arator. 

Pages 92-120 

CHAPTER VII. 
The Ripening of Cream. 

Means of producing lactic acid — Temperature of ripening — 
Amount of acid necessary' — Acid tests — Determination of 
lactic acid in milk and cream — Further effects of ripening — 
Churning cream of different degrees of ripeness — Bad effects 
of over- ripening. 

Pages 121-133 

CHAPTER VIII. 

Churning. 

Viscosity of the milk — Ripeness of cream — Temperature — Nature 
of agitation — Quality of the globules of fat — End of churn- 
ing — Difficult churning. 

Pages 134-143 

CHAPTER IX. 

Finishing and Marketing Butter. 

Washing the butter — Working — Salting — Brine salting — Pack- 
ing and marketing — Composition and quality of butter. 

Pages 144-156 

CHAPTER X. 

Milk for Cheese Making. 

Theory of cheese making — Quality of milk for cheese making — 
Loss of fat — Cooling — Aeration — Ripening — Rennet tests — 
Degree of ripeness necessary — Starters —Rennet — Removal 
of whey. 

Pages 157-172 



xii Contents. 

CHAPTER XL 

Cheddar Cheese Making. 

Setting — Cutting — Heating — Cheddaring — Grinding — Salting — 
Curing — Difficulties likely to occur in eheddar cheese mak- 
ing — Qualities of cheese. 

Pages 173-190 

CHAPTER Xn. 

Varieties of Cheese. 

Home-trade or stirred-eurd cheese — Sage cheese — Young Amer- 
ica — Pineapple — Truckle — American Neufchatel — Phila- 
delphia cream cheese — Limburger — Imitation Swiss — Pre- 
pared cheese — English cheese — Stilton — Emmenthaler or 
Swiss — Edam — Gouda — Roquefort — Brie — Camembert — 

Gorgonzola — Parmesan. 

Pages 191-203 

CHAPTER XIII. 

By-Products of the Dairy. 

Skimmed milk, buttermilk and whey — Milk sugar — Dutch 
cheese — Whey cheese — Cheese food — Wheyn. 

Pages 204-208 

CHAPTER XIV. 

Butter and Cheese Factories. 

Location of creameries —Arrangement of building — Construc- 
tion — Cheese factories — Combined butter and cheese fac- 
tories — Farm dairy buildings. 

Pages 209-220 

CHAPTER XV. 

Statistics and Economics of the Dairy Industly. 

Increase in dairy production — Development of the factory sys- 
tem — Condensed milk - Dairy legislation — Dairy markets. 

Pages 221-230 



Contents. xiii 

APPENDIX. 



Pages 231-236 



A. Useful rules and tests. 

B. Metric system of weights and measures. 

Pages 237-238 

C. Legal standards for milk in the various states — The oleomar- 

garine law — The filled-cheese law — The New York state 
dairy law. 

Pages 239-258 

D. References to Agricultural Experiment Station reports and 

bulletins. 

Pages 259-267 

INDEX. 

Pages 269-2^0 



MILK AND ITS PRODUCTS. 



CHAPTER I. 

THE SECRETION OF MILK. 

The females of all animals that suckle their 
young (class Mannnalia) secrete for this purpose a 
special fluid which is known as milk. It is an 
opaque yellowish white fluid, with a slight alkaline 
reaction and a faintlj' sweetish taste. It consists 
of an emulsion of fats in a watery solution of 
alkaline salts, casein and sugar. It is secreted in 
two special glands situated without the bodj' cavity 
on either side of the median line, and known as 
the mammary glands or mammae. 

Mammary glands. — While, strictly speaking, there 
are but two glands, each gland may be divided 
into two or more lobes, each having a separate open- 
ing ; thus, while there are ordinarily but two simple 
glands in the ewe, mare and goat, in the cow there 
are four or six, in the cat and bitch six to ten, and 
in the sow ten to fourteen. In animals having 
multiple glands, the mammse occupy nearly the whole 
of the lower part of the chest and abdomen. In 
other animals the glands are confined either to the 
chest or abdomen. In many animals each gland 



2 Milk and Its Products. 

or lobe is furnished with a single opening connect- 
ing with a single duct, in others several ducts 
open independently upon the surface of a single 
nipple or teat. The mammary gland is a true 
organ of secretion in the sense that its product (milk) 
contains substances not before existing in the blood, 
that are formed during the process of secretion in the 
gland itself. In the cow the mammary glands are lo- 
cated on the posterior portion of the abdomen be- 
tween the hind legs, and each gland is made up of 
two lobes or quarters, each having a single outlet 
furnished with a single duct, though there are often 
one and sometimes two rudimentary ducts upon the 
rear quarters, and which are occasionally developed to 
such an extent that milk may be drawn from them 
in small quantities. The whole organ is spoken of as 
the udder, and the ducts as teats. While the mam- 
mary gland is essentially a female organ, it is present 
in a rudimentary condition in the males of all mam- 
mals, and in exceptional cases in man and in the lower 
animals the organs of males have developed to such a 
degree as to secrete milk. 

The cow^s udder. — The udder is enclosed in a fold 
of skin, which is here thinner and softer than upon 
other parts of the body, and is supported by a band 
of fibrous tissue that springs from the median line of 
the body and extends through the whole substance of 
the gland. It varies very much in size and shape 
in different animals and in the same animal at dif- 
ferent times. Its size is not always an indication 
of the secreting powers of an animal, since the num- 



structure of the Udder. 3 

ber of true secreting follicles does not necessarily bear 
any relation to the apparent size. The udder in a 
good cow should be large and well developed ; it 
should occupy the whole space between the hind 
legs, extending well up between the thighs and 
well forward upon the helly. It should be held 
firmly against the wall of the abdomen. It should 
be level or nearly so on the bottom, and the four 
quarters should be as nearly as possible equally 
developed and each furnished with a cylindrical per- 
pendicular teat of moderate length. The whole 
organ should diminish rapidly in size as the milk 
is withdrawn. The hair upon the udder should be 
fairly abundant, fine and soft, and abundantly sup- 
plied with a brownish dandruff. 

The substance of the udder is composed of the 
fibrous band, already mentioned, connective tissue, 
fatty tissue, milk ducts or canals, true secreting 
cells (acini, ultimate follicles, alveoli), veins, arte- 
ries, nerves and Ij-mphatics, the whole making up a 
reddish gray mass of spongy texture. 

The udder varies very much, in different indi- 
viduals, in size and shape as well as in internal 
structure and secreting capacity. In some animals 
the amount of connective and fatty tissue is much 
larger than in others. Such udders are said to be 
"fleshy," and while usually of large size and good 
shape, are deficient in true secreting capacity. They 
are firm to the touch, particularly when empty, and 
do not markedly diminish in size when the milk 
is withdrawn. It is generally supposed that such 

B 



4 . Milk and Its Products. 

udders are more subject to inflammations and in- 
flammatory diseases than those with less fatty tissue. 
In many cows, particularly while young, the fibrous 
net -work that supports the udder is held firmly up 
to the under side of the abdomen. If in con- 
nection with this the udder has comparatively little 
connective and fatty tissue, the animal will have 
an udder apparently small, but with large capacity 
for secretion. In old cows, particularly those that 
have been large milkers, the fibrous bands often 
become largely relaxed, so that the udder falls 
nearly to the ground, and appears to be of enor- 
mous size. 

Internal structure of the udder and teats. — The 
teat is simply a canal surrounded by muscular walls 
and closed at either extremity by an involuntary 
sphincter muscle. These muscles, particularly the 
lower ones, vary much in rigiditj^ in different ani- 
mals. Often thej^ are so lax that the pressure of 
a small amount of milk in the canal is sufiicient 
to open them, and the animal leaks her milk. In 
other animals, it requires a strong effort of the 
hand to draw the milk. Where the animal milks 
unduly hard, the rigidity may be overcome by keep- 
ing a smooth wooden plug of sufficient size to 
moderately dilate the opening in the end of the 
teat till the muscle relaxes sufficiently to permit 
easy drawing of the milk, or the muscle may be 
partially divided with the knife in the hands of 
a skilful operator. At the top of the teat, or 
bottom of the udder, there is a small cavity known 



Arrangement of Mill' Ducts. 5 

as the milk cistern, serving to hold the milk 
after its secretion until it is drawn. It is of 
varying capacity, though it seldom holds more 
than half a pint. From the milk cisterns a system 
of canals or so-called milk ducts extends to all 
portions of the udder. These ducts- are larger near 
their opening into the milk cistern, and diminish 
in size as they rise through the udder. They 
branch and anastomose freelj' in all directions, and 
finally end in a group of small sac -like bodies, 
the ultimate follicles. The system of milk ducts 
arising from each teat is practically distinct, 
though there is more or less communication be- 
tween the smaller ducts in the upper portions of 
the two quarters on the same side of the animal. 
This renders it possible to draw a part of the 
milk secreted in the hind quarter from the forward 
teat on the same side, and vice versa. There is 
no communication between the ducts on opposite 
sides of the animal. At the junctions of the 
larger ducts there are greater or smaller enlarge- 
ments, forming small cavities or milk reservoirs, 
which serve the same purpose as the reservoirs 
at the top of the teat. The branching points 
of all the ducts, large and small, are guarded by 
sphincter muscles. These muscles are connected 
with the abdominal muscles of the animal, and she 
is able to more or less completely close them at 
will, and so "hold up" her milk. It requires a 
strong effort on the part of the animal to com- 
pletely close the larger ducts in the lower part of 



6 Milk and Its Products. 

the udder ; a comparatively slight effort is all that is 
necessary to close the smaller vessels. Animals vary 
greatly both in the control they possess over these 
muscles and in their disposition to use it. Very few • 
can completely close the larger ducts, and very many 
rarel.j' exercise whatever power they do possess. Sud- 
den fright, the presence of strange persons or animals 
in the stable, any iiTegularity in the time or manner 
of feeding or milking, and slight feverish conditions, 
particularly sexual heat, are the most cocimon. pro- 
vocatives to holding up milk. There are very many 
cows that contract the habit of holding up the milk 
upon the slightest provocation, and if the habit is 
once formed it is almost impossible to cure it, and 
the result is that the usefulness of the animal as 
a milk producer is largely destroyed, for the reten- 
tion of the milk in the udder interferes greatly 
with the activity of secretion, and in a short time 
permanently lessens it. J 

The ultimate follicles. — The milk ducts, after 
branching and anastomosing in all directions, finally 
end in a group of small sac -like bodies known as 
acini, or ultimate follicles. It is in these small 
bodies that the secretion of the milk takes place^. 
They are about l-30th of an inch in diameter, and 
are found in groups of three to five, with a com- 
mon outlet at the end of each branching duct. 
In form and appearance they present marked 
changes according to the condition of the animal. 
During active lactation they are found in their 
highest development. When lactation ceases, the 



Secretion of Milk. 7 

smaller ducts become much retracted, and the 
follicles shrink in size and finally become rudimen- 
tary, or even entirely disappear, until under the 
stimulus of a succeeding pregnancy, the whole 
gland renews its activity, and the ducts and fol- 
licles regain their former size and appearance. 
New ducts and follicles may also be formed up to 
about the fifth or sixth year, and the power of 
the animal to secrete milk be thereby increased. 
Surrounding the follicles, and intimately attached 
to them, are capillary blood vessels, both veins and 
arteries, and through the cells of the membranes 
making up the walls of all these vessels the fluids 
of the blood freely pass into the cavity of the 
follicles by means of osmosis, or transudation. 
The cavity of the follicle is lined with epithelial 
cells, that during lactation are filled with proto- 
plasm, and are capable of rapid multiplication, 
growth, and degeneration, at the same time that 
the cell contents are undergoing rapid and exten- 
sive changes. 

The secretion of milk. — The milk is formed from 
the blood, partly by the transudation of the blood 
serum directly into the cavity of the milk follicle, 
and partly by a transformation of the contents of 
the epithelial cells lining the cavity of the follicle, 
which at this time are especially active. The 
water passes directly from the capillaries into the 
milk follicles and ducts, carrying with it the min- 
eral constituents in solution and a part^]of the al- 
bumin of the blood serum; but by far the larger 



8 Milk and Its Products. 

part of the albumin is in some way changed dur- 
ing its passage from the capillaries, and appears in 
the cavity of the follicle as the casein of the milk. | 




Fig. 1. Section through alveoli of the mammary gluiid of the dog iu first auU 
second stages of secretion. From Meade Smith, after Heideuhain. 



When milk is being secreted, the lining cells of 
the follicle are in a state of constant activity. 
New cells are constantly being formed by budding 
or fission (the cell elongates, a partition forms 
across it, and the two halves so divided enlarge to 
the size of the mother cell, and there are two cells 
where but one existed before), and older cells are 
as constantly breaking down. While this is going 
on, the cell contents, consisting mainly of protoplasm, 
become changed into a globule of fat, and the 
globules so formed are either extruded through the 
cell wall into the cavity of the follicle, or set free 
by the breaking down and reabsorption of the cell 
wall. In all probability both processes take place. 
Small portions of the fat may also be carried over 
directly from the blood and appear in the milk 
without change. The milk sugar is probably formed 



Incentives to Secretion. 9 

through a chemical change in the contents of these 
lining cells, since but minute quantities of sugar 
are found in the blood. 

Incentives to secretion. — Maternity is the prime 
incentive to the secretion of milk. While there is 
a distinct increase in the development of the mammas 
upon attaining puberty, it is not until pregnancy is 
well advanced that the organ attains anywhere near 
its full development, or that there is any activity 
in the true secreting cells. In the virgin animal, 
and up to within a short time of parturition, the 
cavities and ducts of the udder contain a water}^ 
saline fluid, but true milk does not appear until a 
short time before, and in some cases not until after, 
parturition. The immediate stimulus to the produc- 
tion of milk is the turning of the blood that went 
to nourish the foetus from the arteries of the uterus 
to the arteries of the udder. The pressure of blood 
in the vessels of the udder stimulates the secreting 
cells to great activity, and the cells, hitherto dor- 
mant, begin to multiply rapidly. When this activity 
is first set up, the various processes of secretion are 
more or less incomplete, so that the milk first se- 
creted is very different in character from that se- 
creted afterwards, and is known as colostrum. The 
colostrum contains in the first place considei'ably 
less water than normal milk; in the second place, 
the transformation of albumin into casein is only 
partial, so that colostrum contains large amounts of 
albumin; and finally, when secretion of milk begins, 
the cells of the follicle multiply more rapidly than 



10 3Iilk and Its Products. 

they can be reabsorbed, and portions of partially 
broken down cells break away from the walls of 
the follicle and appear in the colostrnm. Gradually 
the colostrum takes on the character of normal 
milk, and in the course of four or five days the 
change is complete. Other characteristics of colos- 
trum are discussed in detail in the next chapter. 

While maternity is the prime cause of secretion, 
it is not the only means of stimulation to the ac- 
tivity of the udder, nor is it a necessary prerequisite 
to the secretion of milk. The regular removal 
of the saline fluid in the gland of the virgin 
animal, or even the stimulation of the organ by the 
friction of the hand or the suckling of a calf, may 
be sufficient to cause the secretion of milk of nor- 
mal character in considerable quantities. In the 
same way and und(^r the same exciting causes, other 
glands of the body, notably the lymphatics in the 
arm pits and the rudimentary mammge of males, 
have been known to secrete a fluid resembling milk 
in all essential characteristics. 

Amount and duration of ftoiv. — With wild ani- 
mals in a state of nature, the' milk is secreted only 
in amount sufficient for the needs of the j^oung 
animal, and only until the young is sufficiently de- 
veloped to secure its food independently of the 
mother. Under the influence of domestication the 
cow has been brought to increase her flow of milk 
many fold, and the time during which it is se- 
creted has been lengthened until it is almost, and 
indeed is, in some cases quite continuous. A dis- 



Dependence upon Circulation of Blood. 11 

cussion of the agencies by means of wliieli this 
most important result has been brought about 
would open up the whole question of the selection, 
breeding and training of cows, as well as every- 
thing pertaining to the science of foods and feed- 
ing, which is not here possible. There are, how- 
ever, some physiological conditions affecting the 
secretion of milk that may be mentioned. 

Milk is secreted from the blood. The amount 
of milk secreted will, therefore, depend upon the 
amount of blood passing through the udder, and 
this, in turn, will depend upon the number and 
size of the blood vessels, not only in the udder it- 
self, but leading to it and away from it, the vigor 
of the circulation, the supplj' of food to the ani- 
mal, and her capacity to eat, digest and assimilate 
it and turn it into blood. From or shortly after 
parturition, there is a constant tendency of the 
blood vessels in the udder to shrink in size, and 
consequently a constanth' diminishing flow of milk. 
When the period of lactation advances at the same 
time that the pastures are growing more scanty 
and less succulent, this diminution is fairly regular 
and constant, especially after from three to five 
months of the period of lactation have passed. This 
tendency to shrinkage in the size of the blood 
vessels of the udder may be held in check in great 
measure by an abundant supply of nutritious food, 
particularly if it is of a succulent character, and 
it is not at all uncommon to find cows secreting 
milk in regular amount, or "holding out," for eight 



12 Milk and Its Products. 

or ten months. But in this respect the individ- 
uality of the animal plays an important part, so 
that wide variations are seen in different individ- 
uals under the same conditions of food and care. 
After a shrinkage in the flow has once taken place, 
it is extremely difficult to again increase it by 
increased food until after another calving. 

Effect of succeeding pregnancy . — The effect of the 
animal again becoming pregnant is to decrease the 
flow of milk. The cause of this decrease seems, 
in many cases, to be two-fold: First, a sympa- 
thetic effect, following immediately upon conception, 
and secondly, a shrinkage due to a turning away of 
a part of the blood from the udder to nourish the 
growing foetus. This shrinkage does not become 
marked until the fourth or fifth month of preg- 
nancy. In this respect, as in their power to "hold 
out," individual animals show the widest variation. 
With very many the effect of becoming again preg- 
nant is so slight as to be scarcely noticeable ; with 
others it is so great as to materially interfere with 
the usefulness of the animal. 

Incomplete removal of milk. — One of the most 
important means of checking the secretion of milk 
lies in the incomplete removal of milk already se- 
creted. We have already seen that the removal 
of the saline fluid from the ducts of the inactive 
gland is an efficient stimulus to secretion. So, too, 
the presence of milk in the ducts acts as a check 
to further secretion. Further than that, it not 
only checks secretion but is an actual irritant, suffi- 



Regularity of Milking. 13 

cient in mauy instances to give rise to inflammations 
of a serious character. Clean milking is one of 
the most important aids in keeping up and pro- 
longing the flow of milk. 

Regularity and frequency of milking. — While the 
process of milk secretion is a continuous one, it is 
not entirely uniform. Tliere is reason to believe 
that the secretion is cousiderablj^ more rapid while 
the operation of milking is going on, and that a con- 
siderable portion of the whole amount is then secreted. 
On the other hand, the distension of the milk ducts 
and reservoirs by milk already secreted acts as more 
or less of a check upon the activity of the follicles, 
and so lessens the rapidity of secretion. While for 
these reasons it would be inferred that frequent 
milking would lead to increased secretion, the limits 
of such increased secretion are' moderate, and beyond 
a certain point no increased flow of milk is secured 
by increasing the frequency of the milking periods. 
In all cases where the udder becomes unduly dis- 
tended with milk between periods, an increased flow 
will be secured by milking oftener. The common 
practice is to milk twice in the twenty -four hours, 
and the nearer the time can be divided into equal pe- 
riods the more uniform will be the secretion. Where 
more frequent milking is practiced the same principle 
will hold. Not only is regularity in the period from 
morning to night of importance, but regularity in 
the time of milking from day to day is equally so. 
A difference of an hour in the time of milking will 
frequently make a difference of 10 per cent in the 



14 Milk and Its Products. 

amount secreted, and where these irregularities are 
frequent, will soon result in a considerably diminished 
flow. The amount of milk given is also considerably 
affected by the way in which the milk is drawn. 
In general, it may be said that rapid milking is con- 
ducive to a large flow. In any event, the milk 
should be drawn so that no discomfort is caused 
the animal, and in this respect there is great dif- 
ference in milkers. A rapid, uniform stroke, with 
a firm touch on the teat, and a stroking motion to 
the lower part of the udder, gives the best results. 
Babcock has found that certain milkers uniformly get 
not only more but richer milk from the same cow. 
Control of the animal over secretion. — The secre- 
tion of milk is involuntarj'. The animal can no 
more control it than it can control the respiration 
or the circulation of the blood. Yet * there are 
numerous conditions of the animal that have a 
more or less direct effect upon the secretion of milk. 
These conditions have not onlj^ to do with the physi- 
cal condition of the animal — as the supply of food, 
the circulation of the blood, extremes of temperature, 
etc. — but extend in large measure to the nervous 
organization and condition of the animal. We have 
already seen that the animal may by an exercise of 
will more or less completely control the withdrawal 
of milk already secreted ; so, too, there are nervous 
conditions that have a great effect upon the actual 
secretion. Sudden fright, an unfamiliar milker or 
attendant, unusual excitement, sexual excitement, or 
the presence of an animal in heat in the herd, an 



Physical Condition of Aniynal. 15 

unusual amount of exercise, or any one of many 
other causes, may be sufficient to decrease the secre- 
tion of milk one -half in any one day. The eifect 
of such disturbances is usually quickly overcome, but 
their frequent recurrence leads to a permanent diminu- 
tion of the secretion. The nervous organization 
of the animal is a most important factor in deter- 
mining the eifect of these various disturbing influ- 
ences. Many of the animals in which the powers of 
digestion, nutrition and secretion are most highly de- 
veloped are possessed also of a highly developed and 
sensitive nervous system, and hence are easily affected 
by any disturbing condition. With all such animals 
it is of the utmost importance that every condition 
surrounding the animal should be as regular and 
uniform as possible. Other animals of equal capacity 
show a remarkablj' quiet and phlegmatic nervous 
temperament, and are consequently slightly or not at 
all affected by such disturbing influences. Such an- 
imals are of great value to the milk producer, for 
with the utmost care and regularity there are always 
disturbing influences beyond the control of the 
dairyman. 



CHAPTER II. 

COMPOSITION OF MILK. 

The constituents of milk are numerous and of 
diverse character, but may be easily classified into a 
few well marked groups as follows: (a) water, (b) 
fats, (c) substances containing nitrogen (albumi- 
noids), (d) sugar, (e) ash. Excepting the water, they 
are collectively known as milk solids. The solids 
exist partly in solution, partly in semi -solution, and 
partly in suspension in the water. Milk from the 
various classes of animals has the same general 
constitution and properties, and varies only in the 
relative proportions of the various proximate con- 
stituents. Cow's milk is typical of all milks, and as 
it is the only milk used in processes of manufac- 
ture in the United States, all of our discussions 
have reference to it alone. In various other coun- 
tries milk from the goat, ass, mare and ewe is con- 
siderably used, not only as food but for the man- 
ufacture of various products. Indeed the peculiar- 
ities of some of these is supposed to be largely due 
to their having been made from the milk of ani- 
mals other than the cow. Koumiss, made from 
mare's milk in Arabia, and Roquefort cheese, made 
largely from ewe's milk, are noteworthy examples. 

(16) 



Percentage Composition. 17 

All of the milk constituents are more or less va- 
riable in quantity, and manj- of them vary widely; 
hence it is not possible to make a statement of the 
average percentage composition of milk that will give 
more than a general idea of its composition. The 
following are taken from recent authorities in the 
various countries: 

American. English. German. French. 

(Bahcock.) (Oliver.) (Fleischmann.) (Cornevin.) 

Water .... 87.17 87.60 87.75 87.75 

Fat 3.69 3.25 8.40 3.30 

Casein .... 3.02 3.40 2.80 3.00 

Albumin ... .53 .45 • .70 

Sugar 4.88 4.55 4.60 4.80 

Ash 71 .75 .75 .75 

100.00 100.00 100.00 99.60 

The following, from Koenig, shows the range of 
variation of the several constituents in nearly 800 
analyses collected from all parts of the world: 

Maximum. Minimum. 

Water 90.69 80.32 

Fat 6.47 1.67 

Casein 4.23 1.79 

Albumin 1.44 ,25 

Sugar 6.03 2.11 

Ash 1.21 .35 

While the range of variation shown above is 
considerable, some of the constituents, notably the 
fat, may show even greater ranges in milk secreted 
by normal, healthy cows. It is probable that the 
minimum of Koenig is seldom exceeded, but as high 
as 10 per cent of fat has been found in the milk 
of single cows giving a very small quantity. Bab- 
cock states that no analysis showing more than 9 



18 Milk and Its Products. 

per cent of fat is recorded from any cow giving as 
much as 15 pounds of milk per day. Any analysis 
above 7 per cent is extremely rare, and should be 
regarded with suspicion unless well authenticated. 
The mixed milk of herds seldom falls below 3 per 4 
cent of fat and rarely rises above 5.5 per cent. 

Colostrum. — The first milk secreted by the animal 
after parturition is quite distinct in composition and 
physical properties from that produced after the 
secretion has become well established. Such milk 
is called colostrum, and is ordinarily considered 
unfit for consumption or manufacture. Colostrum 
differs from common milk chiefly in its less propor- 
tion of water, in the much greater proportion of 
albumin and ash, and in the presence of small 
organized bodies known as colostrum corpuscles, which 
are probably debris of the cell structure of the gland. 
The percentage of albumin in colostrum is so great 
that it will cause the whole amount of milk to 
thicken upon boiling, and this is ordinarily consid- 
ered a sufficient test for determining the suitability 
of the milk for consumption or manufacture. With- 
in four or five days after calving, the milk loses its 
colostrum character and takes on its normal condi- 
tion. This change is a gradual and progressive one, 
and is more or less dependent upon the physical 
condition of the animal. When the cow is feverish, 
or when there is local inflammation in the udder, 
the colostrum character of the milk is retained 
for a longer period than otherwise. The amount 
of coloring matter present is also considerably 



Specific Gravitu of Jfill'. 19 

greater in colostrum than in normal milk, and the 
percentage of fat varies very widelj-. Usually the 
percentage of fat is less in the colostrum than in 
the normal milk from the same cow, although oc- 
casions are not infrequent where more fat is found 
in the milk immediately after calving than at any 
other time in the whole period of lactation. 

Specific gravity of milk. — Some of the solids of 
milk are heavier than water and some of them lighter, 
milk as a whole having a specific gravity somewhat 
greater than water. The variation in the specific 
gravity is considerable, the range usually given being 
from 1.029 to 1.035 at 60" F., the average being 
about 1.032. In general, the effect of an increase 
in the solids of the milk is to increase its specific 
gravity, though in milk extremely rich in fats (six 
per cent or above) the specific gravity is lessened. 
Formerly, more than at x^i'^sent, it was the custom 
to estimate the quality of the milk by determining 
its specific gravity, but as soon as it became known 
that the specific gravity depended not so much upon 
the amount as upon the character of the solids, a 
determination of the specific gravity became of little 
value. Unscrupulous dairymen soon learned that 
water could be added to milk and fat or cream 
taken from it in such proportions that the specific 
gravity would remain the same as that of normal 
milk. 

TJie fats. — The fat of milk, or butter fat, as it 
is often called, is a mixture of a considerable number 
of separate and distinct fats, no less than six or 



20 Milk and Its Products. ' 

eight being normal to milk, and a considerable fur- 
ther number may be present under various conditions. 
The fats in milk are of two kinds, volatile and non- 
volatile. To the former class belong the various 
normal essential oils that give to milk and butter 
their characteristic odors and flavors, and in addition 
to these normal fats there may be a large number 
of volatile oils that are present in the food of the 
cow, and that impart to the milk the characteristic 
flavors of such foods. 

The volatile fats. — The volatile fats make up only 
a small part of the total milk fat ; in general, some- 
what less than eight per cent of the Avhole. The 
chief normal volatile fats are butyrin, caprin, caproin, 
caprilin and rutin. Of these, butyrin is in much 
the largest proportion and of much the greatest im- 
portance. It is the chief volatile fat of milk and 
butter, and to it are due in large part the character- 
istic flavors and aromas of milk and butter. Butj^rin 
readily decomposes, forming butyric acid, which is the 
chief element in the rancid or " frowy " taste that 
butter acquires upon long standing. 

The volatile fats that are derived directly from 
the food may give either desirable or undesirable j 
flavors to the milk. Thus we esteem the character- 
istic flavors due to the grasses, clover and like fodder; 
on the other hand, the stronger flavors of garlic, 
onions, turnips, cabbage, etc., give to the milk an 
undesirable character. 

The presence of these undesirable flavors in milk 
is often a source of a good deal of annoyance, but 



Effect of Strong -flavored Foods. 21 

with proper precautions the bad results coming from 
them may be greatly lessened, and in many cases 
entirely obviated. Since all of these flavoring oils are 
volatile, they easily pass through all the tissues of 
the animal, and in a comparatively short time pass 
off through the various excretory channels. We shall 
find them present in the greatest amount not only 
in the milk, but in all the tissues of the animal, 
during the time that the fodder containing them is 
undergoing digestion, and by the time the digestion 
is completed the volatile products will have almost 
entirely passed away. If, therefore, sufficient care 
is taken to so time the feeding and milking that the 
milk shall be drawn not less than ten or twelve 
hours after the undesirable fodder has been eaten, 
there will be slight danger of contamination of the 
milk by it. Whereas, if milking occurs within three 
or four hours after feeding, the milk will be 
strongly impregnated with the undesirable flavor. 
Taking advantage of this, and feeding cows immedi- 
ately before or immediately after milking, dairymen 
are often enabled to feed large quantities of turnips, 
and even onions, without danger of contamination of 
the milk. The presence of wild garlic and wild 
onions in pastures is a source of bad flavor in the 
milk in a considerable portion of the country. Where 
this is the case it is, of course, more difficult to 
overcome the bad flavor, but by allowing the cows 
to pasture for a comparatively short time only im- 
mediately after milking, and keeping them up and 
giving them some dry food for three or four hours 



22 Milk and Its Products. 

before milking, tliei'e will be a great deal less an- 
noyance from this source. 

The non -volatile fats. — The non- volatile fats make 
up about 92 per cent of the whole amount of fat, 
and consist almost entirely of three fats, known as 
olein, palmitin and stearin. They are glycerides of 
the corresponding fatty acids, oleic, palmitic and 
stearic, and differ from one another chiefly in their 
hardness or melting point. Olein is liquid at or- 
dinary temperatures ; stearin and palmitin are solid, 
their melting points being about as follows : Olein, 
41° F. ; palmitin, 140° F. ; stearin, 150° F. The 
mixture of the whole, as we find them in ordinary 
butter, melts at from 92° to 96° F. The pro- 
portion of olein varies from 30 to 50 per cent, the 
palmitin making up a large part of the remainder, 
the stearin not rising above 3 or 4 per cent in 
most instances. The following table will give an 
idea of the ordinary proportions and distribution of 
the various fats. 

Olein 42.2 

Stearin and palmitin, togetlier 50. 

Biityrin 7.7 

Caproin, caprilin, myristin, nitin, etc 1 

100.0 

It is asserted that the coloring matter of the 
fat is most intimately associated with the palmitin. 
The fat exists in the milk in the form of an emul- 
sion of extremely small globules, varying in size 
from TF07 to 2 5^00 of an inch in diameter. These 
globules are not surrounded by pellicles, or so- 



SohibiUty of the Casein. 23 

called skins, as was formerly thought, but main- 
tain their form by reason of the surface tension of 
the liquid fat, and also to some extent because of 
a laj^er of more or less condensed casein that im- 
mediately surrounds them. The permanency of the 
emulsion is further increased by the viscous nature 
of the milk serum, due to the presence of sugar 
and other solids in solution. 

Tlie alhuminoids. — The casein is the chief albu- 
minoid of milk, although there is always present a 
small amount of albumin, and, according to some 
authorities, of fibrin. Casein is of prime impor- 
tance in the manufacture of cheese, and it is the 
chief constituent that goes to form tissue when milk 
is used as a food. 

There is a good deal of doubt as to the form 
in which the casein exists. Formerly it was sup- 
posed that the casein is in solution. This idea 
was brought about by the fact that it is impossible 
to filter the casein from the milk, even though it 
is passed through several thicknesses of fine paper. 
Later, though, it was found that when milk is 
passed through a fine porcelain filter a certain part 
is removed, and it was then supposed that there 
were two forms of casein, one of which was in 
solution and the other in suspension in very fine 
particles of a colloidal or gummy character. Still 
later investigations have shown that in all proba- 
bility a large part of the casein is in this extremely 
fine colloidal state. When milk is subjected to 
the action of weak organic or mineral acids, to 



24 Milk mid Its Products. 

rennet or to certain vegetable substances, the casein 
is precipitated in a flocculent mass. Casein is not 
acted upon by heat. The albumin of the milk is 
in all respects similar to blood albumin. It is 
rendered insoluble by a heat of about 180° F., but 
it is not acted upon by weak acids or rennet, and 
in this way it is chieflj' distinguished from the 
casein. The fibrin of milk, if present, is in ex- 
tremely minute quantities. It is supposed to be 
the same as blood fibrin, and coagulates upon ex- 
posure to the air, but is never present in sufficient 
quantity to form a clot, as in the case of blood. 
Its coagulation is hindered by a reduction of tem- 
perature, and it has been supposed that when it does 
coagulate it forms a sort of network of threads 
through the mass of milk. 

The sugar. — Milk sugar, otherwise called lactose, 
exists in solution in the milk serum. It has the 
same chemical composition as cane sugar : that is, 
C12H22O11 + H2O. It crj'stallizes with considerable 
difficulty, and has very much less sweetening power 
than ordinary sugar. Under the influence of vari- 
ous ferments it readily undergoes decomposition, 
each molecule of sugar breaking up into four mol- 
ecules of lactic acid. This change begins in the 
milk almost immediately after it is drawn, and con- 
tinues until about .8 of 1 per cent of lactic acid 
is formed. The presence of lactic acid in this 
amount acts as a check upon the growth of the 
ferments, and prevents the further formation of 
lactic acid, unless the acid is neutralized with an 



Constituents of the Ash. 25 

alkali, when the fermentation proceeds as before. 
Milk sugar does not readily undergo alcoholic fer- 
mentation, but by the action of yeast and some 
other ferments the lactose is "inverted," or changed 
to dextrose and a peculiar substance known as ga- 
lactose, and these readily change to alcohol under 
the influence of the proper ferments. 

The ash. — The ash is the smallest and least 
variable constituent of the milk. It is composed 
chiefly of the phosphates of lime and potash, the 
chlorides of potash and soda, with small amounts 
of phosphate of iron and magnesia. Most of the 
salts are in solution. It seems probable that at 
least a part of the phosphate of lime is, ordinarilj- 
in insoluble form, suspended in the milk in very 
fine particles in connection with the casein. The 
chloride of potash is largely in excess of the 
chloride of soda. This is exactly opposite to the 
proportions of these two salts in the blood. 

Other constituents. — Besides the constituents enu- 
merated above, several other compounds are more or 
less normally present in milk in minute quan- 
tities. 

A small amount of citric acid is said to be a 
normal constituent of milk. 

A peculiar substance called lactochrome is also 
a normal constituent of milk, and gives to it its 
characteristic color. This has been already men- 
tioned in connection with the palmitin. The amount 
of lactochrome present varies under many condi- 
tions, notably the breed of the animal and the 



26 Milk ami Its Products. 

character of the food. Whatever other conditions 
may prevail, the milk is always of a higher color 
where the animals are fed on fresh green forage. 
This has led to the idea that the color of the 
milk is in some way connected with the condition 
of the chlorophyl or green coloring matter of the 
plant. Careno* has suggested that as the chloro- 
phyl undergoes a change when the plant is dried, 
the digestive organs of the animal will have a 
different effect upon it, and so account for the 
difference in color in the milk. 

An albuminoid called lactoprotein has also been 
described in milk. 

Urea to the extent of .001 of 1 per cent 
may also be regarded as a normal constituent of 
milk. 

Variations in quality of milk. — We have already 
seen that the amount of milk secreted may- vary 
greatly under the influence of a large number of 
varying conditions. So, too, we find that there 
are a large number of conditions that affect the 
quality of the milk, meaning thereby the relative 
proportion of the various constituents, and particu- 
larly the proportion of fat to other constituents. 
Some of these changes are regular and progressive 
during the period of lactation. Others are due to 
definite causes, and still others occur from time to 
time to which we have as yet been unable to 
ascribe any definite cause. After about the third 



♦Mileh Zeitung, vol. xxiv. 387. 



Variations in Quality. 27 

or fourth week of lactation the percentage of fat 
in the milk remains nearly constant until the seventh 
or eighth month, or until the quantity of milk begins 
to rapidly diminish ; but while the percentage of fat 
does not markedly change, the character of the fat 
undergoes several marked and characteristic changes. 
The butter globules are largest in size early in the 
period of lactation, and constantly diminish as lac- 
tation progresses, at the same time that they in- 
crease in number, so that the total amount of fat 
is not greatly changed. Early in the period of lac- 
tation there is a larger proportion of olein. In 
some cases it may amount to 50 per cent of the 
total fat. As the lactation progresses the propor- 
tion of olein decreases and stearin and palmitin in- 
crease, until the proportion of olein may fall as low 
as 20 per cent. This change is more marked when 
the animal changes from fresh to dry food, as the 
period of lactation progresses. The hardening of 
the fat and the shrinking in the size of the glob- 
ules are also more marked when the animal again 
becomes pregnant. In the case of cows that are 
milked for a prolonged period, as sometimes hap- 
pens with farrow and spayed cows, the milk often 
becomes abnormally rich, not only in fat, but in 
casein ; and in such cases the fat is usually made 
up of very minute globules. 

It is usually observed that milks drawn at 
night • and morning differ quite widely in the per- 
centage of fat. This is not because there is any 
difference in the milk secreted by night or by day, 



28 Milk and Its Products. 

although when cows lie still there is a larger per- 
centage of water and a correspondingly less per- 
centage of solids in the milk. The difference in 
the milk drawn at morning and evening is due to 
the unequal time that elapses between the periods. 
In general the milk is richest in fat that is draw^n 
after the shortest period, and this has been shown 
to be the case where cows have been milked three 
or four and even five times per day. It is, 
however, not an invariable rule that the milk is 
richest succeeding the shortest period. Not infre- 
quently it has been found that the milk is richer 
after the longer period. In a series of observa- 
tions made by the writer upon 12 cows, ex- 
tending over 221 days, in 72 cases the percentage 
of fat was greater in the morning ; in 114 cases 
it was greater in the evening, and in 35 cases 
there was a difference of .1 of 1 per cent or less 
between the morning and the evening milk. In this 
instance the period from evening to morning was 
about two hours longer. The amount of variation 
that may occur between the morning and evening milk 
is often very considerable. In the great majority 
of cases it is not more than .5 of 1 per cent, 
but variations so great as 2 or 2.5 per cent be- 
tween the milk of one morning and that of the 
preceding or following evening have frequently 
been noticed. It is probable that a part of this 
variation may be explained by the action of the 
lymphatics of the udder in reabsorbing a part of 
the fat when the milk remains for a long time 
in the vessels of the udder. 



First and Last Milk Drawn. 29 

There is also a considerable variation in the 
milk from day to day. This is usually not so 
great as between the morning and evening milking, 
but it not infrequently amounts to 1 per cent. 
Such daily variations may be ascribed to changes 
in the climate or other environment of the cows, — 
the effect of storms, the effect of change of food, 
the effect of slight indispositions, etc.; but there 
are numerous conditions not usually or readily 
recognized by the owner that affect the composition 
of the milk. It has been noted in many instances 
that the normal effect of a slight febrile condition 
of the animal is to largely increase the percentage 
of fat and albumin. If the febrile condition con- 
tinues, and particularly if it grows more severe, 
the fat then falls as quickly as it had risen, and 
to a correspondingly lower point. 

The variation in the percentage of fat in the 
milk first and last drawn is very great. The first 
milk drawn is much the poorer in fat. Differ- 
ences so wide as 1 and 10 per cent of fat in 
the first and last few pints have not infrequently^ 
been noticed. This is due in large measure to the 
fact that the larger globules of fat, being of 
nearlj' the same size as the smaller milk ducts, 
pass along these vessels less readily- than the more 
fluid portions of the milk, and are only drawn 
out with the last milk drawn. The milk first 
drawn has been in the milk cisterns and larger 
vessels for a considerable period of time, and so 
has been subject to the reabsorptive action of the 



30 Milk and Its Products. 

lymphatics for a longer time, which also would 
tend to make it poorer in fat. 

The food also has a considerable influence upon 
the qualitj" of the milk, although the quantity of 
the milk is more easily affected bj^ changes in the 
amount and character of the food than is quality. 
In fact, with cows kept under favorable conditions, 
with an abundant supply of food, it is hardly 
possible to increase the proportion of fat to other 
solids by a change in the food. On the other hand, 
while the amount of the various constituents of 
the milk is not easily affected by the food, the 
quality of the constituents themselves may be 
considerably influenced, notablj' in the case of the 
fat. Certain foods have a ftiarked influence upon 
the character of the milk fat. Thus linseed meal, 
gluten meal and certain other foods make a soft, 
oily fat, while cotton seed meal, the seeds of the 
various legumes and wheat bran make a hard fat. 
Constituents other than the fat are not so readily 
affected in this way. 

Of the constituents of milk, the ash and the 
sugar are the least variable, the fat and albumin 
the most variable, while the casein usually bears a 
nearly constant ratio to the fat. The percentage 
of w^ater also varies considerably. The causes of 
the variation of the fat have already been noticed. 
The proportion of albumin is very largelj' in- 
fluenced by the physical condition of the cow, and 
it has been shown, notabh' by Van Slyke (see 
Chapter X.), that with what may be called normal 



MilJi of Different Breeds. 31 

milk, — that is, milk containing from 3 to 4.5 per 
cent of fat, — the proportion of casein rises or falls 
in almost exact ratio with the fat, but when the 
fat rises above this point the casein does not 
follow in the same proportion. 

The percentage of fat in the milk is also af- 
fected by the age of the cow. During the first 
and second periods of lactation the young cow 
usually gives milk poorer in fat than when she is 
mature. During the years of greatest vigor the 
percentage of fat is fairl}' uniform. In cows of 
advanced age it may sometimes again fall to a low 
point. The breed of the cow also influences very 
largely the percentage of fat in the milk. Cows 
of certain breeds normally give milk much richer 
in fat than others. The variation due to breed 
includes not only the amount of fat, and the color 
and melting point of the fat, but the size of the 
milk globules. In some breeds the milk globules 
are uniformly large, in others extremely small, and 
in still others both large and small globules are 
found. 

While there is a distinct difference in the qual- 
ity of the milk of the different breeds, the dif- 
ferent individuals in the breed also vary largelj^ in 
the quality of the milk. The difference in the 
percentage of fat in milk from different cows of 
the same breed is quite as great as the average 
differences between the breeds ; that is to say, the 
difference between the highest and lowest percent- 
age of fat in the milk of different individuals of 



32 Milk and Its Products. 

the same breed is as great as the difference be- 
tween the average percentage of fat in the breeds 
giving the richest and poorest milk. 

The variations due to the breed of the animal 
extend, of course, in some measure to the butter 
made from the milk. This is particularly true of 
the color and hardness of the fat. But while 
these differences are sufficient in amount to be 
characteristic, they scarcely" affect the quality of 
the butter as a whole. While some partisans may 
contend that the butter made by their favorite breed 
is of superior quality, it would be well nigh impos- 
sible, in any given case, by an examination of the 
butter, to say from what breed of cows it had 
been made. Butter of the very best quality in tex- 
ture, color and flavor may be made from the milk 
of any breed of cows. 



CHAPTER IIL 

THE TESTING OF MILK. 

Milk is so variable iu composition, and so ea- 
sily adulterated, that it frequentlj^ becomes of great 
importance to be able to ascertain with a fair de- 
gree of accuracy the composition of any given 
sample. 

HISTORY OF MILK TESTS. 

Gravimetric analysis. — The most accurate way to 
determine the composition of milk is bj' means of an 
exact chemical analysis. The constituents of milk 
which it is most frequently necessary to determine 
are the total solids and fat. The total solids are 
determined by drying an accurateh' weighed portion 
of the milk at the temperature of _ boiling water 
until it no longer loses weight. The residue is the 
total solids, and its weight, divided by the weight 
of the original amount taken, will give the percent- 
age of total solids. The fats may then be deter- 
mined by extracting the residue with anhydrous 
ether until nothing more is dissolved, and then 
evaporating the ether and weighing the resulting 
fat directly. Various forms of apparatus for mak- 
ing these determinations have been devised by vari- 

(33) 



34 Milk and Its Products. 

ous chemists, a considerable number of which give 
very accurate results. Chief among these methods 
for determining fat and total solids are the Babcock 
asbestos method and the Adams paper -coil method. 
In order that these determinations may be made 
with accuracy, balances of extreme delicacy, and 
apparatus more or less complicated and requiring 
considerable skill in its manipulation, are necessary, 
so that for ordinary commercial purposes they are 
practically out of reach. 

History of milk tests. — Although consumers of 
milk had felt for a long time the necessity of 
some means of protection against dishonest dealers, 
it was not until the development of the factory sys- 
tem of manufacturing cheese (1850) and butter 
(1870) that some means of easily determining the 
composition of milk, particularly as to fat content, 
became important to both producers and manufac- 
turers. From that time on various methods have 
been devised, from the simple expedient of raising 
the cream in a small sample of milk in a graduated 
glass to apparatuses almost as complicated and 
difficult of manipulation as the gravimetric methods 
themselves. 

Cremn gauges. — The simplest and one of the 
earliest methods used to determine the quality of 
milk is to set a small portion of it under such con- 
ditions that the cream would be thoroughly thrown 
to the surface and easily measured. These were 
known as cream glasses, cream gauges, or cream- 
ometers, and to a certain extent served a useful pur- 



Lactometers. 35 

pose ; but it was soon found that the percentage of 
cream depends not so much upon the amount of fat 
present in the milk as upon the size of the globules 
and the conditions under which they are brought 
to the surface, and that the pi^rcentage of cream 
does not necessarily bear a constant relation to the 
percentage of fat. 

Specific gravity. — The determination of the spe- 
cific gravity was next brought into use as a means 
of determining the quality of milk. Inasmuch as 
milk is slightly heavier than water, and as water is 
the most common adulterant of milk, any addition 
of water to it would serve to lessen its specific 
gravity, and would easily be detected by a determi- 
nation of the specific gravity. To determine the 
specific gravity of milk, various forms of specific 
gravity hydrometers, known as lactometers, have 
been devised. They were formerly very much more 
depended upon as a test of the quality of milk than 
at present, and though now we have learned that 
under certain conditions a simple specific gravity 
test may not only be inaccurate, but entirely mis- 
leading, still they are of considerable use for cer- 
tain purposes and in connection with certain other 
instruments. 

Lactometers. — In devising the lactometer, it was as- 
sumed that 1.029 was as low as the specific gravity of 
any unadulterated milk would ever fall ; therefore a 
hydrometer was devised, the scale of which was gradu- 
ated from to 120, the marking the point of pure 
water, or a specific gravity of 1.000, and 100 cor- 

D 



36 



Milk and Its Prodiicts. 



responding to the 
milk, or 1.029. 
If, then, in any 
given sample of 
milk the lactom- 
eter fell to 90, 
it would indicate 
the presence of 10 
per cent of water ; 
if it fell to 75, of 
25 per cent of 
water, etc. This 
form of lactometer 
is now known as 
the common, or- 
dinary or Board 
of Health lactom- 
eter. A second 
form of lactometer 
in common use 
was devised by 
Quevenne, and 
bears his name. 
The scale of this 
hydrometer is or- 
dinarily graduated 
from 15 to 40, the 
29 being coinci- 
dent with 100 up- 



assumed least specific gravity of 



1.005 



1.01O 



1.015 



1.025 



'f 



on the 01 dmarj/ lac- ^jg o. comparison of graduation on lactometer 
+rkm£ii-ar» o-nrl ixri+V. stems : A, hydrometer ; B, ordinary lactometer ; 

lOmeiei ana Wlin O, Quevenne lactometer. 



Relation of Quevenne to Ordinary Lactometer. 37 

a specific gravity of 1.029 upon the ordinary hy- 
drometer. The accompanying sketch (see opposite 
page) shows the relative vakies of the degrees upon 
the ordinary hydrometer, the ordinary lactometer and 
the Quevenne lactometer. With the Quevenne lac- 
tometer the specific gravity of the milk can be at 
once read, a degree upon this scale being equivalent 
to one degree of specific gravity. Since 100 degrees 
upon the ordinary lactometer are equal to 29 degrees 
specific gravity, the specific gravity may be obtained 
by multiplying the ordinary lactometer reading by 
.29 and adding 1,000. Twenty -nine Quevenne de- 
grees are also equivalent to 100 ordinary degrees, 
so that Quevenne readings may be changed to the 
ordinary readings by dividing by .29, and ordinary 
readings may be changed to Quevenne readings by 
multiplying by .29. 

The relative density of milk varies with its tem- 
perature, so that a hydrometer is only correct at one 
given temperature. Most hydrometers are graduated 
for a temperature of 60° F., and the better forms 
have an attached thermometer ; so that if the milk 
to be tested varies from this in either direction a cor- 
rection must be made. As the density increases with 
a reduction of temperature and decreases with a rise 
of temperature, the correction must be subtracted if 
the temperature is too low, and added if the temper- 
ature is too high. The amount of such correction 
for the Quevenne lactometer is .1 of a lactometer 
degree for each degree of temperature, and for the 
ordinary lactometer one lactometer degree for each 3 



38 Milk and Its Products. 

degrees of temperature. In no event should the 
temperature of the milk to be tested be more than 10 
degrees warmer or colder than the standard, and it is 
much better if the temperature does not vary from 
the standard more than 5 degrees in either direction. 
The solids in milk are not all of the same 
specific gravity ; some are heavier and some lighter 
than water. The fats are lighter, the other solids 
are all heavier. The specific gravity of the milk, 
then, depends not onlj" upon the amount of solids 
present in the milk, but also upon their relative 
proportions. The specific gravity of milk may be 
affected by the addition of any substance to it or 
the abstraction of any of its constituents. Since 
some of the constituents of milk are lighter than 
water, their abstraction in whole or in part would be 
followed bj' an increase in densit3\ It will be 
readily seen, then, that if a part of the fats are re- 
moved, the specific gravity of the skimmed or partly 
skimmed milk will be heavier than normal, and the 
addition of a certain amount of water or other sub- 
stance lighter than the milk would only serve to 
bring the specific gravity back to the normal point. 
In this way, if it is done skilfully, water may be 
added to milk, and cream abstracted from it, with- 
out affecting the specific gravitj^ as revealed by the 
lactometer, and a very inferior sample of milk might 
pass as perfectlj^ normal if the lactometer alone 
were depended upon for its detection. Mainly for 
this reason the lactometer has been superseded by 
other and more accurate instruments. 



operation of Test Churns. 39 

Churn tests. — The first butter factories or cream- 
eries were managed upon what is known as the 
cream -gathering system : that is, the cream was 
raised and skimmed upon the farm, and it alone 
taken to the factory. It was soon found that the 
cream varied considerably in the percentage of fat 
that it contained, and, moreover, that a consider- 
able amount of milk could be mixed with the 
cream without being detected by ordinary means. 
In other words, the managers of factories learned 
that cream as it came to them was even more 
variable in its percentage of fat than whole milk. 
In all of the earlier factories the cream was paid 
for simply by measure, and it became necessary to 
devise some means of making an equitable division 
among the different patrons, and of protecting the 
factory from loss. To do this, what was known 
as test churns were devised. At the time of 
gathering the cream, a small sample ( a pint or 
quart) of each patron's cream was taken in a sep- 
arate vessel. These were taken to the factory 
and churned separately in small tin cans, and the 
butter made up from each. The butter -producing 
power of the single pint or quart was taken as a 
measure of the butter value of the whole amount 
of that patron's cream, and the proceeds were ap- 
portioned accordingly. This method was much more 
just than a simple measure of the cream, but it 
was very cumbersome. It required delicate manip- 
ulation in order to make all of the little pats of 
butter of the same water content, and the small 



40 Mill- mid Its Products. 

amounts of butter so made were of inferior com- 
mercial quality, could not be mixed with the whole 
mass of butter, and entailed a considerable loss 
upon the creamery. 

The oil -test churn was an outgrowth of this 
method, intended to remedy its defects, and was in 
a great measure successful. In operating the oil -test 
churn, the individual samples taken from each patron 
were very much smaller, and were taken in small 
glass tubes. These tubes were put in a frame and 
agitated until the fat was di-awn together in a solid 
mass ; the tubes were then immersed in water suf- 
ficiently warmed to melt the fat, and when so 
melted the fat would float upon the surface of the 
liquid in the tube. The tubes were allowed to 
become cool, were then a second time agitated to 
churn anj" particles of fat that had escaped the 
first churning, and the fat remelted ; it then ap- 
peared in the form of a clear layer of liquid upon 
the top of the contents of the tube, and could be 
readily measured. The proportion of melted fat 
so obtained was taken as a measure of the butter 
value of the cream of which it was a sample. 
This test was generally used in cream - gathering 
factories, and was a very fair measure of the 
butter value of the cream. There was always a 
portion of the fat remaining unchurned, but in 
cream it was a small percentage. In milk, how- 
ever, it was a much larger proportion, and the 
oil -test churn was never successfully used for de- 
termining fat in milk, 



Lactobutyrometer and Bioscope. 41 

Inventions for testing milk. — Several instruments 
of European invention have been described for the 
quick determination of the fat in milk. Some of 
them make volumetric determinations of the fat or 
cream ; others depend simply upon the opacity of 
the milk. One or two are in common use in 
Germany and Denmark, but, though most of them 
have been introduced in the United States, none 
have come into general use. The more important 
of these are the following : 

Marchand^s lactobutyrometer. — This is an instru- 
ment for quickly determining, volumetrically, the 
fat in milk. A measured sample of milk is intro- 
duced into a long glass tube graduated at the 
upper end. A certain amount of acetic acid is 
added and thoroughly mixed with the milk, after 
which ether is added to dissolve the fat, and with 
the aid of a small amount of heat the fat is col- 
lected into the upper graduated portion of the tube 
and read off volumetrically. The lactobutyrometer 
was introduced about 1877, and was used with 
more or less success for a time. In certain sam- 
ples of milk it was found to be difficult to get a 
clear separation of the fat, and in certain other 
samples, notably the milk produced from various 
foods, it was found that the results could not be 
relied upon. 

Heeren^s pioscope. — This is a simple little instru- 
ment designed to test the quality of milk by 
means of its opacity. It consists of a hard rubber 
disc, in the center of which is a small depression, 



42 Milk and Its Products. 

and the surronndiiig circle painted in segments of 
varying shades to represent cream, very rich milk, 
normal milk, poor milk, etc. A drop of the milk 
to be tested is placed in the central depression 
and covered with a glass plate, so that a layer of 
uniform thickness is always obtained. The opacity 
of this drop of milk upon the black background 
of rubber is then compared with a corresponding 
segment of the circle. In so far as the fat 
measures the opacity of the milk, this is a fairly 
reliable test ; and, used in connection with a specific 
gravity lactometer, a person with some experience 
can readily detect suspected samples of milk, although, 
of course, it is not possible to estimate very closely 
the amount of adulteration or the quality of the 
milk. The pioscope has been used very generally 
and successfully by milk inspectors and those hav- 
ing the control of citj^ milk supply. 

Feser^s lactoscope is another instrument designed 
to determine the quality of milk by opacity. It 
consists of a glass cylinder, in the center of which 
is fixed a white rod graduated with black lines. 
A certain amount of milk is put into the cj^linder, 
and by its opacitj^ renders the black lines upon 
the central standard invisible. Water is then added 
to the milk in measured quantity until the black 
lines can be seen, the amount of water so added 
indicating the qualitj^ of the milk. This instru- 
ment is more delicate than the pioscope, but it can 
not be so quickly and readily used. The results 
it gives are of very much the same nature and 



Various European Tests. 43 

value as those obtained by the use of the pioscope, 
consequently it has never been used to any great 
extent. 

Soxhlefs method. — In testing milk by this method, 
the fat in a measured quantity of milk is dissolved 
in ether, the specific gravity of the ether solution 
determined, and from this the percentage of fat is 
calculated. The greater the specific gravity of the 
ether solution the greater the percentage of fat, 
and since the difference in the specific gravity of 
fat and ether is considerable, the addition of a 
small amount of fat will perceptibly affect the specific 
gravity, so that the determination is a very delicate 
one. The determination is made in a specially de- 
vised apparatus known as Soxh let's Aerometer. It 
has been widely adopted in Germany, but not at all 
in the United States outside of chemical labora- 
tories. 

BeLaval lactocrite. — This is a machine devised by 
the inventor of the centrifugal separator to esti- 
mate the fat in milk volumetrically. The sample 
to be tested is put in a glass tube with an equal 
amount of concentrated acetic acid containing 5 per 
cent of concentrated sulphuric acid, and the mixture' 
heated for a few minutes, after which it is whirled 
in a centrifugal machine until the fat is brought to 
the center. It is then read off volumetrically. The 
lactocrite gives a very close determination of the 
fat in milk, but it is necessary to have a separator 
frame in which to whirl the apparatus, which makes 
it somewhat expensive, 



44 Milk and Its Products. 

• 
Fjord'' s control apparatus. — This apparatus, in- 
vented by the late Professor Fjord, of Denmark, 
estimates the fat by measuring the solidified cream. 
Glass tubes similar to those used in the oil -test 
churn are secured in a frame and a measured quan- 
tity of milk put in each. The frame holding the 
bottles is then whMed in a centrifugal separator 
frame till the cream is completely separated and 
brought together in a compact mass. This re- 
quires about forty -five minutes. The solid mass 
of cream is then measured with a scale and the 
fat estimated from it by means of a table con- 
structed by the inventor. This apparatus is in 
very common use in Denmark, but has never been 
introduced into this country. 

Development of milk tests in the United States. — Up 
to the year 1888, there had been no apparatus devised 
which would determine the fat in milk accuratelj^ 
easily, cheaply and quickly. None of the methods 
described could in any sense supply the place of the 
gravimetric analysis, even for commercial purposes. 
The oil -test churn came the nearest to it, but that 
was of no use for milk, and at this time the separa- 
tor creamery was beginning to supplant the gathered- 
cream factor}^, and the demand was constantly 
stronger for a means of determining the fat in milk. 
This yesLY also marked the establishment of the na- 
tional grant to Agricultural Experiment Stations in 
each of the states, and one of the first problems at- 
tacked by the chemists of these stations was to de- 
vise a quick method for the determination of fat in 



American Tests. 45 

milk. In the next two years no less than seven dis- 
tinct methods were devised by chemists of Agricul- 
tural Experiment Stations for this purpose. All of 
them were much better than any that had hitherto 
been known, but one was so much in advance of 
any of the others that now it is practically the only 
method used for the quick determination of fat in 
milk. This is the method devised by Dr. S. M. Bab- 
cock, known as the Babcock test, and first published 
in July, 1890. The various tests, in the order of 
their publication, were as follows : 

Shores method. — This method was invented by 
F. G. Short, at that time chemist of the Wisconsin 
Agricultural Experiment Station, and was first pub- 
lished in Bulletin No. 16 of the Wisconsin Agricul- 
tural Experiment Station for Jul}', 1888. In brief, 
the method consisted in converting the fat in the 
milk into a soap by means of an alkali, and then dis- 
solving the soap by an acid, setting free the fat. 
The process was rendered complete by boiling for 
several hours. The determination was made with a 
measured quantity of milk in a glass test bottle with 
a narrow graduated neck, into which the fat was 
raised at the end of the process, and read off volu- 
metrically. Considerably diflftculty was often ex- 
perienced in getting a clear separation of the fat 
from the contents of the tube. The long period of 
boiling was also an important drawback to the 
method. 

The method of Failyer and M^illard. — This method 
was devised by Professors Failyer and Willard, of 



46 Milk and Its Products. 

the Kansas Agricultural Experiment Station, and 
was published in the report of that station for 1888. 
In it the solids of milk were destroj'ed by hj^dro- 
chloric acid and the fat partially separated by means 
of heat. The fat was then dissolved in gasoline, and, 
after evaporation of the gasoline, was measured in 
a graduated portion of the tube in which the opera- 
tion was performed. It gave a clearer reading of 
the fat than Short's method, but required more deli- 
cate manipulation, particularly in heating the acid 
and milk together and in evaporating the gasoline. 
The time required was considerably less than with 
Short's method. 

Parsons^ method. — This method was devised by 
Professor C. L. Parsons, of the New Hampshire Ag- 
ricultural Experiment Station, and published in the 
report of that station for 1888. This method made 
use of caustic soap and a solution of soap and alcohol 
to destroy the milk solids, after which the fat was 
dissolved in gasoline. A measured quantity of the 
gasoline solution of fat was then taken, the gaso- 
line evaporated from it and the fat carefully dried. 
The free fat was then measured in a scale, and by 
means of a calculation, the percentage of fat deter- 
mined. This method gave very good results in the 
hands of several different operators. It, perhaps, 
required a little more delicate manipulation than 
some of the others, and it was considerablj" more 
complicated than Short's method. 

The Iowa Station test. — This test was invented by 
Professor George E. Patrick, the chemist of the Iowa 



BahcocJc Test. 47 

Agricultural Experiment Station, and published in 
Bulletin No. 8, February, 1890, of the Iowa Experi- 
ment Station. In this test the solids of the milk 
were destroyed by a mixture of acetic, sulphuric and 
hydrochloric acids, and the fat brought to the sur- 
face by boiling. The test was made in a flask with 
a narrow graduated neck. A measured quantity of 
milk was put in the flask, a sufficient amount of 
the acids added, and the whole boiled for ten or fif- 
teen minutes. The Iowa Station test was a great 
improvement upon any that preceded it in point of 
simplicity, accuracy and length of time required. 

Cochran^ s method . — This method was invented by 
C. B. Cochran, of the Pennsylvania State Board of 
Health, and published in the Journal of Anal3^tical 
Chemistry, Vol. III., page 381. In this method 
the solids of the milk other than the fat were de- 
stroyed by the use of a mixture of acetic and sul- 
phuric acids, aided by boiling. When the milk 
solids were thus completely disintegrated, the fat was 
brought to the surface by the aid of ether, and then 
the whole mass further boiled until the ether was all 
evaporated. The clear melted fat was then meas- 
ured by transferring it to a vessel with a gradu- 
ated neck. The Cochran method was simple in 
details, but required rather delicate manipulation in 
transferring the melted fat from one vessel to an- 
other. It, however, gave very good results in a 
comparatively short time. 

The BahcocJc test. — This test was invented by 
Dr. S. M. Babcock, chemist of the Wisconsin Agri- 



48 Milk and Its Products. 

cultural Experiment Station, and published in Bul- 
letin No. 24, July, 1890. In point of simplicity, 
accuracy, ease of manipulation and time required, 
this test is so much better than any that have pre- 
ceded or followed it that it is now practically the 
only one in use. To destroy the solids other than 
the fat, Dr. Babcock makes use of a single rea- 
gent, commercial sulphuric acid, of a specific gravity 
of 1.82, and to separate the fat from the remain- 
ing contents of the test bottle centrifugal force is 
used, hot water being added to bring the contents 
of the flask up to the graduated part. The test is 
made in a small flask with a narrow graduated neck. 

The Beimling test. — This method of testing milk 
was devised by Messrs. Leffman and Beam, and is 
sometimes known under their name, though the ap- 
paratus was i)at6nted hy H. F. Beimling, and intro- 
duced under his name. The Beimling test was in- 
troduced in the year 1890, and was essentially like 
the Babcock test, the exception being that instead 
of a single reagent two were used, one ordinary 
commercial sulphuric acid, as in the Babcock test, 
and the other a mixture of amji alcohol and com- 
mercial hydrochloric acid. Largely because of the 
greater inconvenience of using two reagents, the 
Beimling test has fallen into disuse. 

Tests introduced since the BahcocJx test. — Two or 
three tests differing but slightly from the Babcock 
have been introduced since. One of these is known 
as Gerber's method, the invention of a German 
chemist. The form of the testing bottles differs 



Babcock Test. 49 

somewhat from that used by Dr. Babcock ; less 
whirling is required, and the same reagents are 
used as in the case of the Beimling. The DeLaval 




Fig. 3. Hand centrifugal for Babcock test. 

Separator Company has also introduced an appara- 
tus for testing milk which is known as the butyrom- 
eter. In this test a single reagent, sulphuric acid, 
is used to set free the fat. The form of the ap- 



50 Milk and Its Products. 

paratus is different from the Babcock test, a mucli 
higher speed of whirling is used, a smaller sample 
of milk is taken, and the fat is read in a solid 
instead of a liquid form. 

DETAILS OF THE BABCOCK TEST. 

The apparatus used in testing milk by the Bab- 
cock method consists of a centrifugal machine, three 
pieces of glassware and commercial sulphuric acid. 

The centrifugal machine. — Many forms of centri- 
fugal machines are in use, almost every manufacturer 
having his own particular style. It is essential that 
the centrifugal should be substantially made ; that it 
should run smoothly and steadily, either loaded or 
empt}^, and that it should be capable of developing a 
speed of 900 revolutions per minute, with a wheel 
20 inches in diameter. The centrifugals so made 
may be driven either by hand or steam power. In 
the hand -power machines, the motion is transmitted 
both by belts and by friction cogs ; in the latter 
case it is essential that care be taken to prevent 
loss of motion through the friction cogs becoming 
worn. 

In the centrifugals driven by steam turbines, or 
jets of steam delivered against the circumference of 
the revolving wheel, it is much better that the 
steam be applied at some little distance from the 
revolving bottles, otherwise too great a degree of 
heat may be developed in the machine. Those 
centrifugals are most satisfactory in which provision 
is made for the bottles to assume a perfectly hori- 



Tlif Bahcock Test Glassware. 



51 



zontal position when in motion and a perfectly per- 
pendicnlar one when at rest. 

The glassware. — The glassware consists of a flask 




Fig. 4. Steam turlnne centrifugal for Babcoek test. (See opposite page.) 



or test bottle in which the determination is made, 
a graduated pipette for measuring the milk, and a 
short graduated glass cylinder for measuring the 
E 



52 3Iilk and Its Product. 'i. 

acid. The most essential feature of the glassware 
is that it should be accuratelj' graduated. This in 
general can be secured b^- always procuring the 
glassware from a reliable manufacturer or dealer, 




;i 1) c (I e g f h 

Fig. 5. Forms of Babcock test bottles ; a, oi-diuary bottle for whole 
milk ; b, bottle for skim milk, using double charge of milk 

c, Ohlsson, or " B. & W." doitble-neeked bottle for skim milk 

d, e, bottles for testing cream ; /, bottle Avith detachable neck 
g, h, detachable necks for butter and cream. 

though suspected glassware may be tested with com- 
paratively little difficulty. The neck of the ordinary 
test bottle is graduated from to 10, each divi- 
sion being subdivided into five parts. The gradua- 
tion from to 10 will contain a volume of melted 



Testing Butter, Chee.se and Cream. 53 

milk fat equivalent to 10 per cent of the weight of 
the milk taken. Each subdivision of the scale, 
therefore, represents .2 of 1 per cent. The capa- 
city of the graduated portion of the neck is two 
cubic centimeters. The specific gravity of melted 
milk fat at a temperature of 120° F. is assumed to 
l^e .9. The two cubic centimeters will, therefore, 
Y\'eigli 1.8 grams, and in order that the percentage 
of fat read off shall be percentage by weight and 
not by measure, 18 grams of milk must be taken. 
But milk has an average specific gravity of 1.032, 
therefore 18 grams of milk will be contained in 
17.44 culuc centimeters. Two cubic centimeters of 
melted milk fat is, therefore, 10 per cent by weight 
of 17.44 cubic centimeters of average milk. It 
has been found bj' trial that a pipette of the or- 
dinary form graduated at 17.6 cubic centimeters 
will deliver slightly less than 17.5 cubic centimeters 
of milk. The graduation of the ordinary pipette 
should, therefore, be 17.6 cubic centimeters. A 
little less acid than milk is ordinarily required, and 
the acid measure is graduated at 17.5 cubic centi- 
meters, though the amount of acid actually used 
may readily vary two or three cubic centimeters 
either way from this point. 

The fat in the various products of milk may 
be as readil}' determined by means of this test as 
fat in the milk itself, and for these determinations 
various forms of special apparatus have been de- 
vised. (Fig 5.) For testing cream, bottles with a 
capacity greater than 10 per cent are in use. Of 



54 Milk and Its Prodncfs. 

these there are two forms. In one there is a bnlb 
in the middle of the neck, and graduations above 
and below. Ordinarily the lower graduations have a 
capacity of 5 per cent, the bulb a capacity of 10 
per cent, and the upper graduations a capacity of 
10 per cent. The use of this form of bottle re- 
quires that when the fat is read off the bulb should 
always be completely full, and the upper and lower 
surfaces of the fat rest on the upper and lower 
graduations respectivel}'. Another form of cream 
test bottle has a neck much wider than that used 
for ordinary milk testing. Bottles of this form have 
a capacity up to 35 per cent, or even more. The 
graduations are usually not closer than .5 of 1 per 
cent. This form does away with the awkwardness 
of the bulb in the center, but it is not possible 
to read the column of fat to so small a fraction, 
usuall}' to not less than .5 of 1 per cent. For 
testing cream, particularly cream that is rich in fat, 
a special pipette is necessary. The specific gravity 
of cream containing 25 per cent of fat or over is 
nearly that of water, and in testing cream of this 
quality a pipette of 18 instead of 17.6 cubic cen- 
timeters capacity is used. For testing skim -milk, 
where it is desirable to read the small fractions of 
1 per cent, two forms of bottles have been devised. 
In one, two pipettes full of milk are used, and the 
graduations have one -half the ordinary value ; in the 
other form, the bottle has two necks, one of ordi- 
nary width for the introduction of the milk and acid, 
and the other an extremely narrow one, in which 



Calihrating the Glasstvare. 55 

the fat is measured. With this last it is possible 
to read easily to .05 of 1 per cent. 

The fat in the solid milk products, as butter and 
cheese, may also be conveniently determined by the 
Babcock test. Since butter or cheese cannot be 
measured, it is necessary that the sample to be 
tested be weighed. Balances sensitive to .1 of a 
gram are sufficiently delicate. Either 18 grams of 
the substance may be weighed, in which case the 
percentage of fat is read directly from the bottle ; 
or, what is more convenient, any amount from 4 to 
8 grams may be taken. In the latter case, the 
observed reading of fat bears the same proportion 
to the percentage of fat in the substance taken that 
the weight of the sample taken bears to 18 ; and the 
percentage is found by multiplying the observed read- 
ing by 18 and dividing the result by the weight of 
the sample taken. 

In testing butter and cheese, it is convenient to 
use the bottles with detachable necks. A little 
water should be added to the bottle before the 
acid is put in, to aid in the solution of cheese. 

Calibration of glassware . — The correctness of the 
graduation of the glassware may be tested with more 
or less accuracy according to the means at hand. 
The bottles are all graduated on the assumption 
that the tubes are of uniform caliber. The and 
10 points are determined experimentally, and the in- 
tervenihg space equally divided into 50 divisions 
with a dividing engine. The spaces should, there- 
fore, be of uniform size, and if the eye can detect 



56 Milk and Its Products. 

any variation in the size of the spaces such bottles 
should be discarded. Bottles inaccurate in this 
respect are seldom met with now. When the test 
was first introduced they were of frequent occur- 
rence. Bottles may be readily tested with a pipet-te 
of 2 c. c* capacity. Fill the bottle carefully with 
water to the point, wipe out the neck carefully, 
and drop in exactly 2 c. c. of water. It should 
just fill the neck to the top of the graduation. 
If delicate balances are at hand, the bottle may be 
weighed full of distilled or clean rain water to the 
point, and then again filled to the 10 point. 
The difference in weight should be exactly 2 grams. 
The calibration will be still more accurate if mer- 
cury instead of w^ater is used ; 2 c. c. of mercury 
may be measured out, or, what is still better, 
weighed. The specific gravity of mercury is 13.59 ; 
two c. c. will, therefore, weigh 27.18 grams. This 
weighed or measured quantity of mercury is intro- 
duced into a dry bottle, a close-fitting plug is then 
inserted into the neck of the bottle exactly to the 
top of the graduation, the bottle is then inverted ; 
the mercury should exactlj' fill the graduated space. 
The same portion of mercurj^ can then be used to 
test another bottle, and with care to have the 
bottles dry, and to see that all of the mercury is 
transferred each time, a large number of bottles can 
be easily and quickl}^ calibrated. 

The pipettes are best tested by weighing a 
pipette full of either water or mercury ; the former 



* Cubic centimeter. See metx'ic system, iu Appendix. 



Precautions in ISanfjyling Milk. 57 

should weigh 17.6 grams, the latter 239 grams. 
An3' bottle or pipette that varies more than 2 per 
cent from the standard should be discarded, 

Sampling the mill-. — The accuracy of the test 
depends wholly upon getting an accurate sample of 
the milk to be analyzed, A part of the fat so 
readily separates from the milk in the form of 
cream that milk cannot stand even for a short 
time without the upper layer becoming richer and 
the lower layers poorer in fat. Even in milk 
freshly drawn from the cow, that in the upper part 
of the pail will be considerably richer than that 
below. The first step, then, in sampling milk is 
that it should be evenly and thoroughly mixed. 
This is best brought about by pouring from one 
vessel to another : but if the milk has stood over 
night and a layer of tough cream formed, the par- 
ticles of cream will not be thoroughly mixed by a 
single pouring from one vessel to another. In 
all such cases, the sampling must not be done 
until all visible portions of cream have disappeared 
in the mass of the milk. Various forms of sam- 
pling tubes or "milk thieves" have been devised for 
taking samples of milk. They serve the purpose 
fairly well, but are not to be depended upon in 
comparison with a thorough agitation of the milk. 

Where the previous night's milk is carried to the 
factory, the agitation enroute and the stirring inci- 
dent to pouring from the carrying can into the 
weigh can are ordinarily sufficient to cause a pretty 
complete mixture of the milk : but in cold weather 



58 MUJx and Its Products. 

it will frequently be noticed that the cream is not 
thoroughly broken up. Under such conditions, extra 
precautions must be taken to secure perfect sam- 
pling. 

Composite sampling. — In testing milk at factories, 
it is more convenient to take a sample every day, 
and make one test of the mixed samples at the end 
of a week, ten days or two weeks. In order to do 
this, it is necessary to provide a suitable receptacle 
for the milk of each patron. ( Pint lightning -top 
fruit jars or milk bottles, or glass - stoppered sample 
bottles, are most convenient. ) To these bottles is 
added each day a small portion of each patron's 
milk, together with some preservative for preventing 
the milk from souring. The preservatives in com- 
mon use are bichromate of potash, corrosive subli- 
mate, and milk preservaline. Caustic potash and 
soda may also be used. Neumann* claims to have 
had as good results with sodium nitrate as with 
bichromate of potash. Most of these substances are 
poisons, and render the milk unfit for use ; the jar 
should, therefore, be plainly labeled. For many 
reasons the bichromate of potash is to be preferred. 
It gives a distinct color to the milk, and only a 
small quantity of it is necessary to prevent the milk 
from souring. Whatever preservative is employed 
should only be used in quantity sufficient to keep 
the milk from thickening. Of the bichromate of 
potash, an amount sufficient to color the milk a bright 
lemon yellow is all that is necessary. In taking 

* Milch Zeitung, vol. xxii. p. 526. 



Measuring the Milk. 59 

composite samples, an amount proportionate to the 
amount of milk delivered should be taken each day. 
This is conveniently done by the use of the Scovell 
Aliquot Milk Sampler, which, besides serving this 
purpose, gives the advantages of a milk thief in that 
it takes milk from all parts of the vessel. Where 
the milk varies only a few pounds from day to 
day, good results may be obtained by taking a uni- 
form amount of milk for the sample each day, but 
where the variation in quantity is considerable, 
aliquot samplers are much to be preferred. 

Making the test. — In preparing to make the test, 
the same care must be used that the sample shall 
be thoroughly mixed and perfectly uniform, that 
Avas taken in mixing the milk when the sample 
was drawn. In measuring the milk, the pipette 
should either be perfectly dry, or rinsed out with 
the milk to be tested immediately before measur- 
ing the assay. Where a large number of samples 
are to be tested, the latter is found to be the better 
practice. The greatest care should be taken that the 
milk is accurately measured. The lower end of 
the pipette should be placed about midwaj^ of the 
sample of milk and the pipette filled by gentle 
suction at the upper end. The milk should be 
di*awn into the tube above the mark on the neck, 
and the end of the forefinger (.[uickly placed over 
the end of the pipette, the pipette being steadied 
by the thumb and second and third fingers ; hold- 
ing it now on a level with the eye between the eye 
and the light, the pressure on the forefinger 



60 MiJJi and Its Products. 

should be gradually relaxed and the milk allowed 
to flow out of the lower end drop by drop until 
the upper edge of the milk rests exactly upon the 
graduated mark on the side of the pipette. The 
milk is then transferred to the test bottle, and this 
should always be done by placing the end of the 
pipette against the side of the neck of the bottle, 
relaxing the pressure of the forefinger gently at 
first, allowing the milk to flow down the side of 
the neck. If this is not done there is danger that 
the neck will become clogged, and a part of the 
milk be blown out by the escaping air. When 
all of the milk has flowed from the pipette, the last 
few drops should be gently blown into the neck of 
the test bottle. The utmost care must be taken 
that all of the milk is transferred from the pipette 
to the test bottle, and none allowed to escape. 

The acid. — The next step is the addition of the 
acid. The acid should be put into the test bottle in 
such a way that it will rinse down any milk that 
has adhered to the sides of the neck, and pass be- 
tween the milk and the glass in reaching the bot- 
tom of the bottle. As soon as the acid is added, 
the milk and acid should be shaken together with a 
gentle rotary motion until all of the curd is com- 
pletely dissolved, care being taken that no particles 
of curd are thrown into the neck of the bottle. 
The amount of acid used should be about the same 
in volume as the milk, depending somewhat upon 
its strength. Ordinarj- commercial sulphuric acid 
with a specific gravity of 1.82 Avill require about 



Finishing the Test. 61 

17.5 cubic centimeters to completely dissolve 17.6 
cubic centimeters of milk. If the acid is too weak 
the curd will not be completely dissolved, and will 
appear as a curdy, flocculent precipitate mixed with 
the lower part of the column of fat. If the acid 
is too strong, some of the solids of the milk will 
be charred, and will appear as dark -colored, floc- 
culent particles, either mixed with the fat or im- 
mediately under them, when the test is completed. 
Slight differences in the strength of the acid muy be 
overcome by adding a little more or a little less, ac- 
cording as it is too weak or too strong, but satis- 
factory results cannot be depended upon unless the 
acid is of the right strength; viz., 1.82 sp. gr. 
Convenient hydrometers may be secured for a tri- 
fling amount, so that any one may be certain of the 
strength of his acid. The sulphuric acid should 
be kept tightlj^ corked in a glass -stoppered bottle, 
because when exposed to the air, it takes up water 
rapidh', and soon becomes too weak. While it is 
not necessary that the suli^huric acid should be chemi- 
cally pure, some of the cheaper grades of commer- 
cial acid often contain impurities that seriousl}' 
affect the results, causing black specks to appear in 
the neck of the bottle. A reasonably pure commer- 
cial acid should always be used, and can be secured 
at a trifling cost above the impurer forms. 

Whirling, — When the acid has been added and 
thoroughly mixed with all of the samples, they are 
put into the centrifugal machine and whirled steadily 
for five minutes, At the end of this time the ma- 



62 



Milk and Its Products. 



--B 



chine is stopped, and the bottles are filled with 
warm water to the bottom of the neck. They are 
then whirled a second time for two minntes, when 
water is again added np to about the 8 per cent 
mark on the neck of the bottle, after 
which the}' are given a whirl for one min- 
ute. The bottles are then taken out and 
cread as rapidl}^ as possible. 

Reading. — The reading should be taken 
at a temperature between 120° and 150° 
F., at which temperatures the fat will be 
completel}^ fluid. The test should be made 
in a room at a temperature not less than 
70 F., or if the room is much colder 
some means should be taken to prevent 
the bottles from, becoming cool until all are 
read. Much skill and facilitj^ can be 
attained by practice in reading the bottles 
rapidly and accurate!}'. In reading the 
bottles, the reading should be made as 
^/vx\^ shown in the diagram, the lower reading 
Fig. 6. Dia- froui tlic cxtremc lower curved surface 
of Babcoek (ri, Fig. 6), and the upper reading from 

test hottle ; 

the reading tlic cxtrcmc top ot the columu of fat, 

should be, . , t r./. 

made be- (/>, not f, Fig. 6), tlic diiierence between 

tween the . . 

points a-b, the lowcr and upper reading giving the 

not a-c. 

percentage of fat. The reason for read- 
ing in this way is that a small amount of residual 
fat is left mixed with the other fluids in the bottle. 
This is composed of the smaller globules of fat, and 
the amount is practicallj^ uniform, and has been 



-A 



Estimation of Solids not Fat. 68 

found to represent about the amount occupied by 
the curved surfaces in the neck of the bottle, 
due to the capillary attraction between the fat and 
the glass. 

Cleaning the glassware. — Good results cannot be 
secured unless the glassware is kept clean and 
bright. This can easily be done with very little 
trouble. As soon as the bottles are read, and while 
they are still hot, the contents should be emptied 
out. The hot acid and water will carry out with 
it the larger part of the fat in the neck of the 
bottle. The emptied bottle should then be rinsed 
once in warm water and once in hot water containing 
some alkali, either washing soda or any of the va- 
rious washing powders, and then rinsed with either 
warm or cold water until they are perfectly clean. 
With these precautions no difficult}' will be expe- 
rienced in keeping the bottles clean and bright. 

By the use of the lactometer in connection with 
the percentage of fat, a close approximation to the 
percentage of total solids, or solids not fat, may be 
made. Numerous formulas for this purpose have 
been devised. Their application is explained and il- 
lustrated in Part A of the Appendix. 



CHAPTER IV. 

THE FERMENTS AND FEBMENTATIOXS OF MILK, 
AXD THEIR CONTROL. 

Milk, when it is first di^awu, is a limpid fluid 
with a slight odor, mildly sweetish taste, and faint 
alkaline reaction. In fact, milk often shows the 
amphoteric reaction ; that is, it will give the acid 
reaction with blue litmus paper and the alkaline 
reaction with red. Almost immediatelj^ after it is 
drawn, milk begins to undergo a change, and within 
a short time will show a distinct acid reaction. 
The degree of acidity increases with the age of the 
milk. Soon changes begin in the other milk con- 
stituents, and in a comparatively short time, the de- 
composition is so great that the milk can no longer 
be used for food. The sugar is the first constit- 
uent of the milk to undergo change, afterwards 
the albuminoids are attacked, and lastly the fats. 
These changes are not due to any instabilitj' of the 
organic compounds in the milk, but to the effect 
of various vegetable germs that gain access to the 
milk after it is secreted, and, living and growing 
in the milk, bring about the changes mentioned. 
These changes are called fermentations, and the 
agents that bring them about ferments. Milk con- 
taining no germs of fermentation, or milk from 

(64) 



General Characters of Bacteria. 65 

which they have all been removed, is said to be 
sterile. The germs found in milk belong to the 
lowest orders of the vegetable kingdom. Most of 
them are included in the bacteria, although many 
yeasts and moulds are frequently found in milk. 

The bacteria. — The bacteria are extremely minute 
bodies consisting of a single cell filled with protoplasm. 
They are of three general forms, — spherical (coccus); 
rod -like or cylindrical (bacillus), and curved or wavy 
(spirillum). They reproduce by fission; that is, the 
cell elongates slightly in the direction of its longer 
axis, and a partition is formed across tlie cell trans- 
versely, and two individuals exist where there was 
but one before. These may break away and form 
separate bacteria, but often they are kept together 
in various wajs. Many forms are endowed with 
motion, and all require a liquid or semi -liquid me- 
dium for growth and development, though many 
may exist for long periods of time in a drj^ condi- 
tion. Like other plants, in order to grow and de- 
velop, the bacteria must have suitable food. They 
require for their sustenance carbon, hydrogen, oxy- 
gen and nitrogen, together with small amounts 
of mineral matters. Organic compounds are more 
available for food supply than simple inorganic 
salts. Substances like sugar and the various al- 
buminous compounds are admirably suited for their 
food. In ordinary milk nearly all kinds of bacteria 
find an adequate and easily available food supplj' 
in a medium favorable to their growth, so that not 
only the forms of bacteria ordinarily found in milk, 



66 Milk and Its Products. 

but almost any others, will readily live and grow 
should they gain access to milk. Nearly all forms 
of bacteria are sensitive to conditions of tempera- 
ture. The range of temperature in which they 
thrive the best and grow most rapidly is rather 
narrow, though there is a considerable range above 
or below, in which they will still grow and develop. 
The temperature at which any given germ will grow 
most rapidly is called the optimum temperature, and 
the optimum temperature varies widely with the 
various classes of organisms, though by far the 
larger number of bacteria find their optimum point 
between 75° to 100° F., and a higher temperature 
not only stops their growth, but if sufficiently high 
kills them outright. A temperature of 135° F. kills a 
large numl)er of germs. Very few are al)le to live 
above a temperature of 180°, and none can with- 
stand the temperature of lioiling water, 212°, for 
more than a few minutes. If heat is accompanied 
by moisture it is much more effective, so that heat 
applied in the form of live steam is the best means 
of destroying the life of these germs. Under the 
influence of cold the germs become inactive, and 
some kinds are killed by a sufficient degree of cold, 
but very many kinds are able to withstand any 
degree of cold possible to be produced for long pe- 
riods of time. 

Under certain conditions bacteria are able to as- 
sume an inactive condition, or spore form. In do- 
ing this, the protoplasm shrinks into a hard, glisten- 
ing mass, and contracts toward one end of the cell, 



Distribution of Bacteria. 67 

or the wall cell tliickeiis and. encloses the proto- 
plasm. In the spoi-e condition the bacteria are in- 
active, but are able to endure much greater extremes 
of heat, cold or moisture than when active. When 
the conditions of growth become again favorable, the 
spore again becomes active, or is said to germinate, 
and the vital processes are resumed. 

Bacteria are widelj' distributed through nature. 
In fact, there are verj^ few places where they may 
not be found. They are so light and small that 
they float readily in the atmosphere, particularly w^hen 
accompanied by particles of dust. Thej^ are found 
in all rivers and streams, upon the surface of the 
earth, and upon all organic matter. In fact, they 
are universally distributed. By far the larger num- 
ber are not only perfectly harmless but positively 
beneficial. They serve to transform dead organic 
matter into its original condition, and so act as 
scavengers. Others, like the milk ferments, bring 
about specific changes in some definite substances, 
while still others, a large class, are the sxiecific 
causes of various diseases in men and animals. 

Presence of hacteria in milk. — In ordinary milk, 
bacteria are always present in large numbers. These 
gain access to the milk from the atmosphere, from 
the bodies of the animal and the milker, through 
contact with the vessels into which the milk is 
drawn, and to some extent through the udder of the 
animal. The milk when secreted is sterile. So 
far as is known, no bacteria can pass through the 
digestive organs and blood vessels of the animal 

F 



68 Milk and Its Products. 

and appear in the milk. If the iidder is the seat 
of disease due to the growth of bacteria, such bac- 
teria may find their waj^ into the milk ducts and 
infect the milk. In one other way the animal may 
be said to be a source of infection with bacteria. 
The end of the teat of the animal is always more 
or less moist. Bacteria coming in contact with 
such surface, moistened with milk, find there not 
only food in proper form for their growth, but a 
temperature sufiicient to make them active. They 
begin to multiply, and, working their way through 
the orifice of the teat, find milk in larger supply, and 
a temperature still more favoral)le for their growth. 
They increase and multiply, under such conditions, 
with remarkable rapidity, and so work their way 
upward through the milk cistern and into the larger 
milk ducts, so that the milk first drawn from the 
animal always contains a greater or less number of 
bacteria. For this reason it is not an easy matter 
to secure perfectly sterile milk dire(;t from the cow, 
though with great care in disinfecting the udder 
and removing the larger part of the milk from it, 
perfectly sterile milk has been obtained. 

Kinds of hacto-ia in )nilk. — Almost any of the 
known forms of bacteria may live and grow and oc- 
casionalh^ be found in milk. Normally, however, com- 
paratively few forms of bacteria are present. The 
greater part of these are forms which cause various 
changes in the constituents of milk, and are known 
as ferments, and the changes which they induce as 
fermentations. Beside these fermentations, there may 



Kinds of Milk Ffrn(f)ifafions. 69 

be found in the milk the bacteria of any germ dis- 
ease with which the animal may be afflicted, or which 
may be carried into the milk through the atmosphere, 
the water used in cleansing utensils, or the persons 
of individuals suffering from the disease. 

The fermentations of mill'. — The normal fermenta- 
tions to which milk is subject may be conveniently 
divided into three classes. First, those which feed 
upon and cause changes in the milk-sugar, known as 
lactic fermentations. Second, those that feed upon 
and cause changes in the albuminoids of the milk ; 
these in turn are of two classes, peptogenic and pu- 
trefactive. Third, those which attack the fats, and 
are known as butyric fermentations. Besides these, 
which may be called normal fermentations, in that 
they will easily occur in any sample of milk if left to 
itself, there are a large number of other fermentations 
w^hich may be called abnormal, from the fact that 
the}^ occur only in isolated localities, or from time 
to time. These abnormal fermentations include one 
which causes the casein of milk to coagulate without 
the development of lactic acid, known as sweet curd- 
ling ; another which causes a peculiarly ropy or slimy 
condition of certain constituents of milk ; still an- 
other that results in the formation of an intensely 
bitter product in the milk ; an alcoholic fermenta- 
tion, and several fermentations which result in the 
production of various colors, collectively known as 
chromogenic fermentations. An illustration of this 
class is seen in the well-known "bloody bread," 
which is caused by the growth of Bacillus procUgiosus. 



70 Mill' ami Its Products. 

Tliis germ is occasionallj^ found in milk, and imparts 
to it a red color which is easily confounded with 
the red color due to the presence of blood from a 
wounded udder. A single germ rarely occasions 
more than a single fermentation. Often two or more 
are combined in the fermentation, and in many cases 
there are a large number of different germs that 
bring about the same fermentation. This is notably 
true of the lactic and putrefactive fermentations. 
The effect of the various fermentations is such as to 
destroy the value of the milk as such, if thej^ are al- 
lowed to proceed to any great length ; but the manu- 
facture of butter is greatly aided by many of these 
fermentations, and the presence of certain germs is 
absolutely indispensable to the manufacture of cheese. 
Relation of fa ilk hacteria to the human system. — By 
far the greater number of germs ordinarilj- found in 
milk are absolutely harmless, and may be taken into 
the human sj'stem in large numbers with perfect 
impunity, the germs of specific disease excepted, and 
with these latter it is the products formed from their 
growth rather than the germs themselves from which 
danger comes. There are probably no germs normally 
found in milk that may be classed as harmful. This 
is also true of a considerable number of fermen- 
tation products resulting from the growth of the 
germs in the milk. Many of these products give 
to the milk or its product an unpleasant taste or 
phj'sical appearance, but are otherwise perfectly 
harmless. There are, however, certain germs which 
produce a fermentation which results in the forma- 



The Lactic Acid Germ. 71 

tion of poisonous products. These products are the 
causes of the serious or even fatal results that fol- 
low the consumption of milk, cheese, ice-cream, or 
other products containing" them. They are collect- 
ively known as ptomaines. To one in particular, 
that has frequently been found in cheese, the name 
tjTotoxicon (cheese -poison) has been given. They 
have been studied by Vaughn* and others, but 
their origin is still obscure. The germs producing 
these poisonous products are of comparatively^ in- 
frequent occurrence. 

In general, the various classes of fermentations do 
not readily take place at the same time. The active 
growth and development of one germ acts more or 
less as a retarding force upon the growth and de- 
velopment of other germs. 

Lactic fermentations. — Under this group we include 
all of those germs which, living and growing in 
milk, feed upon the sugar, causing it to change to 
lactic acid. It was formerly supposed that the forma- 
tion of lactic acid in the milk was entirely due to the 
action of a single germ, described by Hueppe, and 
called Bacillus acicli-lactici, or the lactic acid germ. 
It is now known that there are at least twent}' different 
germs that may produce lactic acid, and in all prob- 
ability there are many more. The lactic acid germs 
are the most common and most numerous germs 
found in milk, and ordinarily the lactic fermentations 
are the first to take place. They begin their opera- 



* Vjiughu-Novy. Ptomaines aud Leucomaines, Philadelphia, 1896. 



72 Milk and Its Products. 

tions almost immediately after the milk is drawn, and 
continne until the maximum amount of lactic acid has 
been produced. In the lactic acid fermentations one 
molecule of milk-sugar (C12H22O11 — H2O) breaks up 
into four molecules of lactic acid (CsHeOs) without 
the formation of anj^ secondary or by product. The 
presence of the lactic acid serves to coagulate the 
casein, so that curdling of the milk is always an 
accompaniment of the lactic fermentation after it 
has reached a certain stage. The presence of lactic 
acid is unfavorable to the growth of the ordinary 
germs of lactic fermentation, and when a certain 
amount of lactic acid has been formed (about .8 of 1 
per cent of the whole milk), the further develop- 
ment of lactic acid ceases. In milk of ordinary 
qualitj', this occurs when about one -fourth of the 
milk-sugar has been changed to lactic acid. If the 
acid be neutralized with an alkali, the fermentation 
will then proceed until another portion of milk-sugar 
has been changed to lactic acid, showing that the 
lactic acid simply prevents the growth of the germs, 
and does not kill them. Lactic acid germs are most 
active at temperatures between 80° and 100° F.; at 
temperatures below 80° they gradually lose their ac- 
tivity, and below 50° little or no lactic acid will be 
formed. At these low temperatures they are simply 
inactive, not dead. At a temperature of 105° F., 
the lactic germs become inactive, and a large propor- 
tion of them are killed at a temperature from 135° 
to 140° F. In milk, lactic acid fermentation means 
simply souring, and it renders the milk unfit for use, 



Putrefactive Fermentations. 73 

almost wholly because the taste is unpleasant to 
the ordinary palate. A large amount of lactic acid 
is, perhaps, injurious to young and delicate or weak 
digestive organs, but ordinarilj' is harmless. Lactic 
acid fermentations are extremely important in the 
processes of both butter and cheese manufacture, 
and their relations to these processes will be dis- 
cussed in detail in the proper place. 

Fermfuiatlons affecihig the albununoids. — These in- 
clude ordinary putrefactive fermentations, peptogenic 
fermentations, and fermentations resulting in the for- 
mation of poisonous products. These fermentations, 
as a rule, do not thrive in the presence of a strong- 
lactic fermentation, so that ordinarily they do not 
manifest themselves in milk unless the conditions are 
peculiarly favorable for their development and un- 
favorable for the development of lactic acid. Many 
of the putrefactive fermentations will go on at a 
lower temperature than the lactic fennentations do ; 
hence it is often found, when milk is kept at a low 
temperature in order to keep it from souring, that 
after a certain time it V)ecomes l)itter or foul -smell- 
ing. This condition is caused by some one of the 
characteristic putrefactive fermentations. The putre- 
factive germs also readily take on the spore form, 
and in this condition are not so readily killed by 
heat. The putrefactive fermentations usually result 
in the formation of bitter or other unpleasant flavors 
and disagreeable odors, and they are frequently ac- 
companied bj' a considerable evolution of gas. Pep- 
togenic fermentations are those which exert a pep- 



74 MilJi- and Its Products. 

tonizing or digestive action upon the albuminoids. 
By their action the casein is first coagulated, and 
finally liquefied or changed into a peptone. 

Butyric fermentations. — The butyric ferments at- 
tack the fats, and result in the formation of bu- 
tyric acid. They produce the peculiar condition 
found in cream and butter known as ranciditj', and 
do not usually manifest themselves very strongly in 
the milk. 



Control of Fermentations. 

Since fermentations always occur in milk that is 
kept for any considerable time, and since they exert 
so powerful an influence, not onlj' upon the milk 
but upon the products manufactured from it, the 
question of their control is one of ]3rime importance. 
The three chief means of such control are : First, 
prevention of infection ; second, prevention of the 
growth of germs already present ; third, destruction 
of germs already present. 

Prevention of infection . — The greatest source of 
infection comes from the bodj' of the animal and 
from the air of the stable. The germs are alwaj^s 
present, adhering to the hair of the animal, and par- 
ticularly to any particles of dust or dirt. In order, 
then, that the animal shall not be a source of infec- 
tion, it is necessary that she be carefully curried 
and the udder, teats, flank, thighs and lower parts 
of the belly wiped off with a damp cloth immediately 



Prevention of Infection. 75 

before milking. It is of course necessary, also, that 
the hands and clothes of the milker should be as 
carefulh' attended to in this respect as is the body of 
the cow. The bacteria find in the excrements abun- 
dant food for growth and development, and are al- 
ways found in large numbers where such excrements 
are allowed to collect ; and when dirt of this sort ac- 
cumulates and becomes dried, the dust floating in the 
air always carries with it large numbers of germs. 
The germs are also found in large numbers accom- 
panying the dust arising from hay and other dried 
forage. This being the case, it is essential not only 
that the stable should be kept scrupulously clean, 
but that the air should be free from dust, partic- 
ularly at times when milking is going on. Thor- 
oughly sweeping and then sprinkling the stable 
floors an hour or two before the milking will mate- 
rially lessen the germ content of the milk. 

Next to the stable, the dairy utensils are an im- 
portant source of infection with bacteria. They be- 
come attached to the seams and corners of the ves- 
sels, and are not dislodged even with the most careful 
cleaning, and when the fresh, warm milk is drawn 
into such vessels the germs immediately begin to grow 
and develop. The most scrupulous care must, of 
course, be taken in cleaning any vessels in which 
milk is contained, but no vessel can be considered 
safe so far as conveying germs is concerned unless 
it has been exposed to the action of live steam for 
at least three minutes, and then kept in a secure 
place until needed for use. With these precautions 



76 Milk and Its Products. 

in regard to the animal, milker and utensils, milk 
may be secured with a minimum number of bacteria. 
The difference in the number of bacteria in milk so 
drawn, and in milk carelessly drawn, may easily 
amount to a difference of eighteen to twenty -four 
hours in keeping quality under like conditions. 

Holding at low temperatures. — If milk be immedi- 
ately cooled to a temperature of 40° F., or thereabouts, 
very little fermentation will go on, though it will be 
frequently found that after three or four days the 
milk or cream may have a more or less disagreeable 
flavor, due to the presence of some germs that de- 
velop slowly even at low temperatures. If low tem- 
peratures are to be depended upon as a means of 
keeping fermentations in check, it is, of course, of 
prime importance that every precaution should have 
been taken to prevent the access of germs to the 
milk in the first place. The fewer germs the milk 
contains to begin Avith, the more effective will low 
temperatures be as a means of preservation. With 
care in both these respects, milk or cream may be 
kept in a fresh and merchantable condition for a 
week or ten days. 

Destruction of germs in the mill'. — A large number 
of chemical agents is more or less destructive to 
germ life. Many of them are so violent in their 
action as to destroy the milk as well as the germs, 
but there are many which are destructive to germ 
life, with no effect upon the composition, odor or 
flavor of the milk ; but all of these without excep- 
tion are more or less injurious to the human sys- 



Antiseptics and Disinfectants. 11 

tern, particularly if tliey are used coutinuously, even 
though only in small quantities. Of the compounds 
which may be used for this purpose, formalin, saly- 
cilic and boracic acids and their derivatives are un- 
doubtedly the least injurious, but their use is not 
to be recommended under any circumstances. Some 
attempts have been made to utilize the electric cur- 
rent as a means of destroying germ life in milk ; 
but they have so far xDroved ineffectual, and in- 
stances are reported^ where electrolysis of the milk 
constituents occurred where a continuous • current was 
employed. Heat, then, is the only available agent 
that can be used for the destruction of germs al- 
ready present in the milk. This destruction of germs 
in milk or any other fluid by means of heat is called 
sterilization. In order to absolutely sterilize any sub- 
stance, it is necessary that it should be subjected 
to a heat of 212° to 240° F. for one hour on each 
of three successive days. This will kill not only the 
germs that are in active growing condition, but any 
spores that may be present. A lower temperature, 
175° to 212° F., will kill actively growing germs, but 
even at this temperature chemical changes are set up 
in the milk which give rise to flavors known as 
boiled or cooked flavors, that are disagreeable to a 
large number of people. In order to overcome the 
bad effects of heating at such high temperatures 
another process, known as pasteurization, is used. 
Pasteurization. — The name is taken from Pasteur, 



*L'Industrie Laitiere, April 1896. 



78 Milk and Its Products. 

who discovered and used the process in controlling 
the fermentations of wine and beer. It differs from 
sterilization only in the degree of heat used, and, in 
fact, may be properly called an incomplete or partial 
sterilization. The destructive effect of heat upon 
germ life depends both upon the degree of heat and 
the length of time to which the germs are exposed. 
A large number of germs are killed at temperatures 
from 133° to 140° F., while others are killed at tem- 
peratures varying from 150° to 165° F. These latter 
temperatures include the germs of all of the ordinary 
ferments and most of the germs of specific diseases, 
including that of the tubercle bacillus. Since the 
tubercle bacillus is the disease germ most likely to be 
present, milk is ordinarily considered to be safe from 
disease germs when it has been pasteurized at a tem- 
perature sufficiently high to destroy- it. This is a 
temperature of 149° F. for thirty minutes, a tem- 
perature of 155° F. for fifteen minutes, or a tempera- 
ture of 167° F. for ten minutes, and these temperatures 
have come to be looked upon as standard pasteuriz- 
ing temperatures. Milk may be heated to 165° F., 
if quickly cooled afterwards, without developing a 
boiled taste ; so that it is possible that milk be 
rendered safe from the germs of disease and free 
from the ordinary- germs of fermentation without 
developing in it a boiled taste. But in order to 
pasteurize milk safely, it is necessary that means 
should be provided for cooling rapidly from the 
pasteurizing temperatures to 50° F. or below. 

Milk carefully pasteurized, as above described, will 



Apparatus for Pasteurization. 79 

remain sweet thirty -six to forty -eight hours longer 
at ordinary temperatures than milk not pasteurized, 
from which germs have been excluded with ordinary 
care. 

The problem of successful pasteurization, then, 
depends upon the means of raising the milk in a 
short time to the required temperature, holding it 
there uniformly for ten or twentj^ minutes, and then 
cooling it rapidly to 50° or below. Several forms 
of apparatus have been devised for this purpose. 
Some of them are fairly perfect, but most of them 
are lacking in some important point. With the pres- 
ent activity in regard to this subject we shall un- 
doubtedly have in the course of a year or two, much 
more perfect apparatuses for this purpose than are 
at present available. The perfect pasteurizing ma- 
chine should cover the following points : Quick, 
perfect and uniform heating of the milk ; perfect 
control of the temperature ; quick and uniform cool- 
ing ; compact form ; ease of cleansing ; absence of 
pumping arrangements ; security against re -infection 
during the process. 

Selection of milk for pasteurization . — For the best 
results in pasteurizing, it is also essential that the 
milk be as fresh and free from fermentations as 
possible. Russel and Farrington have found* that 
milk that has developed as much as .2 of 1 per 
cent of lactic acid is too sour for satisfactory^ re- 
sults. Inasmuch as this amount of acid cannot 



♦Wisconsin Agr. Exp. Station, Bulls. 44 and 52. 



80 Milk and Its Products. 

readily be detected by the senses of smell or taste, 
Farrington's alkaline tablets offer a very convenient 
means of selecting milks that are snitable or un- 
suitable for pasteurizing purposes. For this purpose 
it is convenient to make the tablet solution (see 
Chap. Yii.) by dissolving one tablet in each ounce 
of water, or one tablet in 30 c. c. of water. Then 
with a cup or other convenient vessel and a small 
measure of any suitable size, the comparative acid- 
ity of different milks can be readily and quickl}- de- 
termined as follows : Put a measiu^e full of milk 
into the cup and add two measures of the tablet 
solution. If the color disappears, more than .2 of 1 
per cent of lactic acid is present, and the milk is too 
sour for pasteurizing purposes. If the milk remains 
pink, less than .2 of 1 per cent of lactic acid is pres- 
ent, and the milk may be safely used. If it is 
desirable to measure the amount of acid, each meas- 
ure of solution maj' be roughly taken to represent 
.1 of 1 per cent of acid. Thus, if the pink color 
remains when one measure of the solution has been 
added, the milk contains .1 per cent of acid. If it 
require four measures of the solution before the pink 
color is permanent, the milk contains A per cent of 
acid. A convenient measure for this purpose is made 
bj^ soldering a piece of stiff wire to the side of a 
No. 10 cartridge shell, after the manner of a milk- 
measuring dipper. 



CHAPTER V. 

MARKET MILE. 

In general, any conditions which make milk 
of better qualit}' for manufacture, also make it of 
better quality to be consumed as milk. These 
conditions are not only those which have to do with 
the composition of the milk, but any other influences, 
as feed, health, care of the cows, or conditions of 
cleanliness. Several conditions affect the quality of 
milk intended for consumption as such. In the 
first place, it must be of high qualitj^ so far as 
the composition is concerned. Second, it must be 
secreted from healthy cows, fed on pure food and 
kept in clean stables. Third, it must be so treated 
that the fat does not readily separate from the other 
solids, and it must not readily undergo fermentation. 
Last of all, it must be clean. 

Cleanliness. — Since cleanliness is equally impor- 
tant, whether the milk is intended for consumption 
or manufacture, it is well to take this up in detail 
first. All vessels used to contain milk should be 
heavily tinned ; pails, cans, and the like, that are 
of the kind called ironclad are preferable on ac- 
count of durability. An efficient means of attain- 
ing cleanliness is in avoiding seams in the utensils. 

(81) 



82 Milk and Its Frodncts. 

This is secured by the use of the pressed or seam- 
less vessels wherever possible, and when it is not 
possible to use these, by taking care that the joints 
are completely and smoothly filled with solder. In 
ordinary pails as found in the market this is never 
done, and it is a matter of considerable importance 
to the i^urchaser that all such seams be resoldered 
before using. The tinware should be kept bright 
and perfect. So soon as anj' rust spots make their 
appearance, an entrance is given into the soft iron 
for germs and small particles of decaying matter, 
which are in consequence removed with much more 
difficulty. Milk is much more easily removed from 
vessels when it has not been allowed to become 
dried upon their surface. If rinsed as soon as 
emptied, tin vessels may be much more easily cleaned 
than if allowed to stand for several hours. For 
such rinsing, lukewarm water is much preferable to 
cold or hot water. Cold water does not so readily 
unite with the milk as warm wafer, and hot water, 
by coagulating the albumin, may cause the milk to 
stick or "cook on" to the sides of the vessel. The 
process of cleaning vessels that have contained milk 
should be : First, to rinse them thoroughly in luke- 
warm water ; second, to wash them thoroughly with 
the aid of some good soap or alkali, in water as 
hot as the hand will bear ; third, to thoroughly 
rinse in hot water ; fourth, to expose to live 
steam from one to two minutes ; fifth, exposure, if 
possible, in bright sunlight from two to three hours. 
With these precautions, not only will the tinware be 



Methods of Securing Glean Milk. 83 

kept clean and bright, but no germs will find a 
resting place in the crevices. The use of much 
strong alkali is inadvisable, as it serves to cloud 
and tarnish the tin, giving it a dull appearance. If 
the vessels are exposed to sterjn until they are 
thoroughly hot, and then placed in such position 
that they will drain, no other drying will be neces- 
sary. 

Having taken every precaution that the vessels 
are thoroughlj^ cleansed, the prevention of access 
of dirt to the milk in process of milking is impor- 
tant. To this end, the body, especially the lower 
part of the bellj^ and udder, of the cow should be 
thoroughly brushed and preferably dampened just 
before milking. The hands of the milker should 
be clean and his clothes free from dust, and the 
air of the stable should be free from dust. If 
the stable floor is dampened, it will not only aid 
in this respect, but in summer time will materi- 
ally reduce the temperature of hot and overcrowded 
stables. With these precautions, we may expect to 
secure milk containing a minimum amount of dirt ; 
but with all these precautions, more or less dirt will 
find access to it. And immediately after milk- 
ing, as much as possible of this dirt should be 
removed by at once straining the milk through a 
brass wire strainer of not less than fifty meshes to 
the inch and three or four thicknesses of loosely 
woven cotton or woolen cloth. The cloth strainer 
not only removes fine particles of dirt, but also 
entangles a considerable number of germs, and hence 
G 



84 



Milk and Its Products. 



these strainers should be cleansed with great care, 
and should be frequently renewed. 

Treatment after drawing. — So soon as the milk is 
drawn, it should be rapidly brought to a temperature 
slightly below the surrounding atmosphere. While it 
is being cooled it should be stirred to prevent the 
cream from rising, and in milk that has been cooled 
in this way there will be comparatively little tendency 
afterward for the cream to separate from the milk. 
Milk so treated is in an ideal condition for consump- 
tion, even though the consumer may consider the 
quality poor because of the slight tendency of the 
cream to form on the surface. 

Aeration of milk. — Milk when drawn from the cow 
contains a certain amount of dissolved gases. These 

gases contain more or less 
of what is known as animal 
odor, the amount of this 
odor depending yqyj largely 
upon the physical condition 
of the animal at the time 
the milk is di^awn. Some- 
times the amount is very 
slight and scarcely notice- 
able, at other times it is so 
great as to be extremely of- 
fensive. These gases and 
the accompanying odor are 
^ , easily removed from the 

star milk cooler and 

aerator. milk by cxposurc of the 




Fig. 7 



Good Influence of Aeration. 



85 



milk to the air during the process of cooling, and to 
this extent aeration of the milk is an advantage. 
Various forms of aerators and combined aerators and 
coolers have been devised, manj^ of which are simple 
and effective, and the best results follow their use. 
In order to secure these results by 
aeration, however, it is necessary 
that the apparatus used for aeration 
should expose the milk thoroughly 
to the air, should not be cumber- 
some, and should be simple and ea- 
sily cleaned; moreover, the process 
of aeration should always take place 
in the purest atmosphere possible. 

Delivery of the milh. — In ordi- 
nary practice in the smaller towns 
and villages, and to a considerable ^^s. 8. "champion" 

milk cooler and aera- 

extent m the larger cities also, the ^or. 
milk is placed in cans in which it is transported 
from the dairy, and is measured out in small quan- 
tities to each customer from the cans in which it was 
originally placed. Where care is taken to cool the 
milk, as described, and during the process of serving 
the customers to keep the contents of the cans well 
stirred, substantial justice is done each individual cus- 
tomer in the matter of giving him the due proportion 
of cream and skimmed milk. This has been well 
shown in a trial made at the Cornell University 
Agricultural Experiment Station* several yeai's ago, 




♦Cornell University Agricultural Experiment Station, Bulletin No. 20. 



86 



Milk and Its Products. 



the interesting results of which are quoted below in 

full detail : 

To determine just how much variation there is in the fat 
of milk served to the different patrons of a route by dipping, 
a member of the Station staff accompanied a milkman as he 
went upon his route, and as the milk was about to be 
served to various patrons, took samples for analysis. The 
dipper, such as is ordinarily used by milkmen, was provided 
with a long handle, so that it rested on the bottom of the 
can when not in use. The milk was not stirred except by the 
motion of the wagon and the raising of the dipper. Twelve 
samples were taken, and yielded to analysis the following per- 
centages of fat : 



Taken from Can A. 



To. 1 . 


. 4.52 


*' 2 . 


. 4.43 


*' 3 


4.41 


*' 4 . 


. 4.32 


" 5 . 


. 3.85 


" 6 . 


. 5.05 


'' 7 . 


. 4.15 


'' 8 . 


. 4.02 


" 9 . 


. 4.05 


" 10 . 


. 4.94 


" 11 . 


. 4.78 


" 12 . 


. 4.85 



^1 



Taken from Can B. 



Taken from Can C. 



Taken from Can D. 



The milk was contained in four 30 -quart cans, marked 
A, B, C and D. The samples were taken as follows: 

No. 1. — Taken from A at 5.50 a. m., within a few rods 
of starting. 

No. 2. — Taken when the milk in A was half gone, at 
6.10. Seventeen dips had been made since No. 1 was taken, 
and three -fourths of a mile traveled. 

No. 3. — Taken from the bottom of A at 6.20. Twelve dips 
had been made since No. 2 was taken, and three-fourths of a 
mile traveled. 

No. 4. — Taken from the top of B at 6.10, three-fourths of 
a mile from starting. 



Variations in Quality in Diiyj^ing from Cans. 87 

No. 5. — Taken from the middle of B at 7.20. Six quarts 
ha^d been added to B at 6.35, and two and one -fourth miles 
traveled between taking samples 4 and 5. 

No. 6. — Taken from the bottom of B at 7.55. One and 
three-quarter miles traveled since taking sample 5. 

No. 7. —Taken from the top of C at 6.20, one and one- 
half miles from the start. 

No. 8. — Taken from the middle of C at 6.50. One mile 
had been traveled since taking No. 7. At 6.35 six quarts re- 
maining in the bottom of A, and about an equal quantity- 
bought of another dealer, had been added to C. 

No. 9. — Taken from the bottom of C at 7.00. Fifteen 
dips had been made, and a half mile traveled, since 8 was 
taken. 

No. 10. — Taken from the top of D at 7.50. 

No. 11. — Taken from the middle of D at a time when 
the wagon had stood still for four minutes, with the dipper 
resting on the botton of the can. Time, 8.15, and one mile 
traveled since 10 was taken. 

No. 12. — Taken from the bottom of D. 

A second and third trial gave similar results. 







SECOND 


TRIAL. 






a. 


b. 


Average. 




Sample 1 . 


. . 4.86 


4.78 


4.82 


(Before starting.) 


Sample 2 . 


. . 4.71 




4.71 


(Top of can.) 


Sample 3 . 


. . 4.82 




4.82 


(One-third gone.) 


Sample 4 . 


. . 4.83 


4.74 


4.78 


(Two-thirds gone.) 


Sample 5 . 


. . 4.73 


4.82 

THIRD 


4.77 

TRIAL. 


(Bottom of can. ) 




a. 


b. 


Average 




Sample 1 . 


. . 4.20 


4.16 


4.18 


( Top of can. ) 


Sample 2 . 


. . 4.11 


4.00 


4.05 


(One -fourth gone.) 


Sample 3 . 


. . 4.13 


4.01 


4.07 


(One -half gone. ) 


Sample 4 . 


. . 4.15 


4.04 


4.09 


(Three -fourths gone 


Sample 5 . 


. . 4.01 


4.00 


4.00 


(Bottom of can.) 



88 



Milk and Its Pi^oducts. 



These results were abundantly confirmed by a sim- 
ilar series made by Dean in Canada*. 

The removal of the covers of the cans in the 
dusty and dirty streets always results in considerable 
contamination of the milk, hence the practice of 
putting the milk into bottles upon 
the farm, and delivering these bot- 
tles intact to the consumer, has 
rapidly increased since its introduc- 
tion, some ten j'ears ago. When 
the bottles are used, the milk should 
be i)ut into them as soon as it is 
di'awn, strained and cooled ; they 
should then be .sealed and kept in a 
cool place until ready for delivery. 
This method of delivery, although 
it entails a greater expense in outfit 
and transportation and a consider- 
able loss from breakage, is much to 
be preferred to the old manner. 
Milk so handled, and ke^Dt at a 

Fig. 9. "Common ^ , , , . _o -, ^^o 

Sense " milk shipping temperature between 45 and 50 
F., should be in good condition 
sixty hours after it is drawn. Its life can be pro- 
longed by pasteurization, and the liability' to ti-ans- 
mission of diseases through the milk at the same 
time reduced to a minimum, but whether pasteuriza- 
tion should be relied upon for these purposes is 
still somewhat of an open question. In so far as 
immunity from diseases which may be present in the 




* Ontario Agricultural College, Bulletin No. 66. 



Healthfulness of Skimmed Milk. 89 

cows is concerned, official inspection of the herds 
is undoubtedly a greater safeguard than dependence 
upon pasteurization or sterilization ; and so far as 
the liabilitj^ of transmission of other diseases is con- 
cerned, the milkman who is careless in regard to 
the cleansing of his utensils, would quite as likely be 
careless in the pasteurization or sterilization process, 
so that reliability of the milkman is an important 
factor in the purity of the milk supply, no matter 
what other precautions are taken. 

Qualify of milk for consumption. — The fat is the 
most variable and the most valuable constituent of 
the milk, so that milk is ordinarily considered to be 
of value for human food in proportion to the amount 
of fat it contains, but where it is to be used as 
a food in large quantities, the fat may frequently 
be present in too large quantities for the digestion 
of many persons. Milk containing about 4 per 
cent of fat is probably an ideal food for the gen- 
eral mass of human beings. If there is above 5 
per cent of fat the other solids are somewhat out 
of proportion, and many are likely to have trouble 
with their digestion from using large amounts of 
such milk. On the other hand, if there is less 
than 3 per cent of fat, the casein and other solids 
are in too great proportion to the fat, and are less 
readily digested. The question of the healthfulness 
of milk from which a large part of the fat has been 
removed is one frequently discussed. The removal of 
the fat does not thereby in any way injure the other 
solids ; they are still there, and still as useful for 



90 Milk and Its Products. 

food as before the fat was removed, only in con- 
suming such milk as food the fat must be supplied 
in some other way. For the person of vigorous 
digestion, who for reasons of economy desires to 
supply the fat required by his system in some 
cheaper form than that of milk fat, skimmed milk is 
a wholesome and nutritious article of diet, which 
furnishes to the system almost the same sort of 
nutrients that lean meat, eggs, or foods of like na- 
ture do, and no one should be debarred by legisla- 
tive or municipal enactment from using such an article 
of food if he so desires. 

Control of milk supply. — Since milk is so extremely 
variable in quality, and is so easily adulterated ; 
since often considerable variations are not readily 
detected ; above all, because the amount of milk 
used by any given person or family is compara- 
tively small, the consumer of milk is almost 
wholly at the mercy of the producer and dealer, and 
must rely for a good product very largely upon their 
honor. The state has recognized this, and to pre- 
vent imposition by unscrupulous people, has in 
various ways sought to regulate the sale of milk and 
like products. The chief means used has been to 
establish arbitrary standards of quality, and to subject 
to fine those dealers whose goods should be found 
to be below the required standard. The standards 
established by various states and municipalities have 
varied widely. From 2.5 to 3.7 per cent of fat, 
and from 11.5 to 13 per cent of total solids, have 
been the minimum requirements. (See Appendix C.) 



Legal Standards for Milk. 91 

These standards, while efficient in securing honest 
dealing where they are rigidly enforced, nevertheless 
may work injustice, so far as the honesty of the 
dealer is concerned, under various circumstances, 
and may prevent the production and sale of a com- 
paratively low quality product at a reasonable price. 
It would seem, therefore, that the best means of reg- 
ulating the traffic in milk would be, not to set up 
an artificial standard to which all must come, but 
to require each individual dealer to guarantee his own 
standard, and hold him responsible if his milk were 
found below. In this way it would be possible to 
sell milk of various qualities, from strictly skimmed 
to heavy cream, upon a graduated scale of prices, 
with exact justice to every one. 



CHAPTER VI. 

SEPARATION OF CREAM. 

Cream is that part of milk into which a large 
portion of its fat has been gathered. It is com- 
posed of the same constituents as milk, but thej^ 
are not in the same or any constant relative pro- 
portion. Cream is separated from milk to be con- 
sumed as food, and, as a matter of convenience, in 
the manufacture of butter. The separation of cream 
is always attended with some loss of fat. The per- 
centage of fat in cream may varj^ anywhere between 
8 and 70 per cent. Cream of good quality for com- 
mercial purposes should contain from 18 to 25 per 
cent of fat, and very rich cream contains from 35 to 
40 per cent of fat. Cream is composed of glob- 
ules of fat, with such part of the water and solids 
as adhere to them. Its separation from the milk 
is effected by means of the difference in specific 
gravity between the globules of fat and the milk 
serum. The fat in the milk is in the condition 
known as an emulsion ; that is, in the form of minute 
globules, which are kept from running together and 
coalescing by means of the surface tension of their 
particles and the viscosity of the liquid in which 
they float ; therefore, any condition of the milk 

(92) 



Systems of Separating Cream. 93 

which tends to increase the surface tension or the 
viscosity will act as a hindrance towards the sepa- 
ration of the cream. While the viscosity of the milk 
serum prevents the particles of fat from uniting 
into a mass, still the particles have considerable free- 
dom of movement in the milk, and being of a less 
specific gravity, of course are acted upon with less 
intensity by any force to which the milk is subjected. 
If the milk is allowed to remain at rest in a 
vessel, the force of gravity, acting with different in- 
tensities upon the globules of fat and the milk serum, 
will cause the particles of fat to gather together 
near the surface of the liquid. In so gathering, 
they carry with them certain of the milk con- 
stituents, and the layer of fat globules and adher- 
ing particles we call cream. From time immemo- 
rial, and until within a very recent date, the 
force of gravity, acting in the way indicated, has 
been the only means used for separating cream from 
milk. Now machines are in use that effect a sepa- 
ration of the cream from milk by means of centrif- 
ugal force, and at the present time we have three 
systems of separating cream ; namely, by gravity 
acting upon a thin layer of milk in a shallow vessel, 
known as the Shallow Pan System ; secondly, by 
gravity acting upon a deeper mass of milk, usually 
submerged or partially submerged in water, known 
as the Deep Setting System ; and thirdl}', bj' ma- 
chines making use of centrifugal force, known as 
the Centrifugal or Separator System. The quality 
of the cream for consumption or for purposes of 



94 Milk and Its Products. 

manufacture is not affected either one way or the 
other by any of these three systems, so that their 
relative economy rests wholly upon the complete- 
ness, cost and ease of separation. 

Since the separation of cream from milk is al- 
ways attended with some loss of fat, it is pertinent 
to inquire as to the necessity of any separation of 
the cream when butter is to be made. It is per- 
fectly possible to manufacture butter directly, by 
churning whole milk without separating cream, and 
undoubtedly the first churns were skins of animals, 
into which the whole milk was placed and then 
agitated until the butter was brought ; but under 
good conditions it is not possible to so completely 
remove the fat from the milk by a churning process 
as by a creaming process ; so that while there is 
some loss in separating the cream, there is usually 
a greater loss in churning the butter from the whole 
milk. Even when the loss of fat in the butter- 
milk is no greater than the loss of fat in the 
skimmed milk, the greater amount of labor required 
to churn the whole mass of milk still renders cream- 
ing an economical practice in the manufacture of 
butter. 

Gravity creaming. — In separating cream by force 
of gravity, there is a greater loss of fat, a longer 
time required, and the various conditions affecting 
the milk have a greater influence upon the creaming 
than when centrifugal separation is used. The 
conditions of the milk that affect the creaming by 
the gravity process are : First, the size of the fat 



Gravity Processes of Creaming. 95 

globules ; second, the amount of solids not fat in 
the milk ; third, the character of the solids not 
fat. The larger the fat globules the more readily 
they separate from the milk, since the larger the 
sphere the less the ratio between the surface and 
the mass, so that a large fat globule meets with pro- 
portionately less resistance because of the viscosity 
of the milk than a small one. The size of the fat 
globules is to a great extent a characteristic of the 
breed and individuality of the animal, but cows 
newly calved secrete larger fat globules than those 
in advanced periods of lactation ; consequently we 
find that the milk from new milch cows is more 
readily creamed than from those long in milk. 
The amount of solids not fat affects creaming by 
the gravity process because of the difference it effects 
in the specific gravity of the fat and milk serum. 
The solids not fat are all heavier than water, and 
in the milk are in a state of solution or semi -solu- 
tion ; hence, an increase in the amount of solids not 
fat increases the specific gravity of the milk serum 
in which they are dissolved, and makes the differ- 
ence between the specific gravity of the fat and 
milk serum greater and the separation of the fat 
easier. The proportion of solids not fat is in- 
fluenced by the period of lactation and, to a con- 
siderable extent, by the character of the food. Cows 
far advanced in lactation often give milk extremely 
rich in solids not fat. Cows fed on diy food give 
milk containing less water than those fed on watery 
or succulent foods. In so far as these conditions 



96 Milk and Its Products. 

increase the amoiiut of solids not fat, we shonld ex- 
pect snch milk to be more easily creamed, but the 
favorable effect of the increase of solids is more 
than counterbalanced by the unfavorable effect of 
the character of the solids. Of the solids not fat, 
albumin, casein, sugar and ash increase the viscos- 
it}' of the milk in the order named, and of these 
the casein is more subject to variation, so that the 
increase in the proportion of solids not fat ordi- 
narily means an increase in casein, and this means 
a largely increased viscosity. And the increase in 
viscosity tends to prevent the separation of the fat 
more than the increase in specific gravity tends to 
aid it. In general, the conditions which bring about 
an increase in the viscositj" of the milk occur at the 
same time as the fat globules are growing smaller, so 
that we find a wide range of variability in the ease 
and completeness with which cream may be separated 
by gravity process. 

Shallow pan creaming. — This is the oldest method 
of separating cream from milk, and notwithstanding 
the rapid changes that have taken place in cream- 
ing methods since the introduction of centrifugal 
separators, large amounts of butter are still made 
from cream separated in this way. The conditions 
most favorable for a complete separation of the fat 
in the shallow pan system are, that the milk should 
be put at rest in the pans as quickly as possible 
after it is di^awn, that it should cool with a fair de- 
gree of rapiditj" to a temperature of 60° F., and that 
it should remain as nearly as may be constantly at 



Shallow Pan System. 97 

that temperature for at least thirty -six hours. 
Further, since the milk must remain for so long a 
time, it is essential that the atmosphere to which it 
is exposed be pure and free from currents of air 
and particles of dust. These conditions can be 
secured in a clean, cool, well ventilated cellar. 
In the shallow pan system, the depth of milk should 
be from 2 to 4 inches. Occasionally water, usually 
running water, is used to secure a quick cooling 
and more even temperature surrounding the milk, 
and when this is done the depth of the milk may 
be increased to 4 or 6 inches. Under the shallow 
pan system, the cream is separated from the milk 
by removing it from the Surface with a thin flat 
instrument, usually made of tin, and called a 
skimmer. In this method of removal, it is not 
possible to completely remove all the cream that has 
risen to the surface, and in removing the cream 
more or less of the milk is taken with it, so that 
in the process of skimming there is a considerable 
loss of fat and a thin cream is always obtained ; 
but even if the losses in the skimming operation 
could be obviated, the separation of the particles of 
fat in the shallow pan system is less complete than 
in either of the others. Under ordinarily good con- 
ditions, 20 per cent of the fat in the milk is lost 
when the shallow pan system is used. Skimmed milk 
containing less than .5 of 1 per cent of fat is 
rarely obtained under this system. 

Deep setting sijstem. — About thirty years ago it 
was discovered that if milk could be set in vessels 
when first drawn, and rapidly cooled to a tempera- 



^S Milk and Its Products, 

tare of about 40° F., and held at that temperature 
for twelve to twenty - four hours, not only could 
the depth be increased from 4 to 20 inches, but the 
separation was much more complete in a shorter 
time. In order to bring about quick cooling, ves- 
sels not more than a foot in diameter were used, and 
water, either from cold springs or containing ice, 
was used as the refrigerant. Two essentials, then, 
for complete creaming by this system are the rapid 
and immediate cooling of the milk to 40° F., and 
a sufficient supply of ice to maintain this tempera- 
ture for twenty - four hours. Under these condi- 
tions the fat may be so completely separated that 
not more than .2 of 1 per cent of fat is left in the 
skimmed milk. Various devices have been used, 
the best known of which is the Cooley system, in 
w^hich the cans are not only surrounded by ice- 
cold water, but completely submerged in it, the 
chief effect of the submerging being to guard the 
milk against contamination through the atmosphere. 
The same conditions as to the character of the milk 
affect completeness of separation in both the shallow 
pan and deep setting systems, but no completely 
satisfactory explanation has ever been assigned as a 
reason why the fat globules should rise more 
rapidly and more completely through 20 inches of 
milk at a temperature of 40° F. in the deep setting 
system, than through 4 inches at a temperature of 
60° -70° F. in the shallow pan system. 

It has been asserted that because water is a 
better conductor of heat than fat, it will cool more 
rapidly than the fat, and will increase in density 



Theory of Deep Setting System. 99 

till its maximum densitj^ is reached at about 40° F., 
at which temperature the difference between the 
specific gravity of the water or milk serum and the 
fat will be at its greatest, and the separation of the 
fat for that reason promoted. But while the water 
does cool faster than the fat, the fat shrinks or 
increases in density much faster than the water, 
so that the difference in specific gravity between the 
two is no greater, and in fact less, at low tempera- 
tures than at high ones. Further, the viscosity of 
the milk serum is much increased at low tempera- 
tures, so that the favorable influence of low tempera- 
tures cannot be explained upon these grounds. 
Arnold* attempted to explain the favorable influence 
wholly upon the relative contraction of the fat and 
serum, as follows : 

Water is a better conductor of heat than fat ; hence when 
the temperature of milk varies either up or cIowti, the water 
in the milk feels the effect of heat or cold sooner than the 
fat in the cream does, therefore the cream is always a little 
behind the water in swelling with heat or shrinking with cold, 
thus diminishing the difference between the specific gravity of 
the milk and cream when the temperature is rising, and in- 
creasing it when the temperature is falling. 

But that this explanation is, not sufficient, Bab- 
cock t has shown thus : 

Though it is true that water is a better conductor of heat 
than fat, the small size of the fat globules renders it impossible 
that, under any circumstances, there can be more than a small 
fraction of a degree difference between the temperature of the 
fat and that of the milk serum. Moreover, within the limits 
of temperature practical for creaming (90° F. to 40° F.), the 



* American Dairying, p. 210. 

tWisconsiu Agricultural Experiment Station, Bull. 18, p. 24. 

H 



100 Milk and Its Products. 

coefficient of expansion of butter fat is more than three times as 
great as that of water, so that in order to maintain the same 
relative difference in their specific gravities, when the tempera- 
ture is falling, the milk serum must cool more than three times 
as rapidly as the fat. In other words, when the milk serum has 
cooled from 90° F. to 40° F., or through 50°, the fat globules 
should have lost less than 17°, and should still have a tempera- 
ture of over 73° F., a difference between the temperature of the 
fat and serum of more than 33°. Such a condition is mani- 
festly impossible, but any less dift'erence than this would cause 
the fat to become relatively heavier than at first, and would 
operate against the creaming. 

On the whole, the most satisfactory explanation of 
the good effect of the low temperature in the deep 
setting system is that advanced by Babcock,* that 
the presence of fibrin in milk, especially when it has 
coagulated in the form of threadlike masses, permeat- 
ing the fluid in all directions, offers a considerable 
obstacle to the rising of the fat globules. The sudden 
reduction of the temperature quickly after the milk 
is drawn, by preventing the formation of these 
fibrin clots or threads, aids in the separation of the 
fat. This would be entirely satisfactory were it not 
for the fact that it has been shown that while it 
is usually of advantage to cool the milk imme- 
diately after it is drawn, in some cases, at least, 
the setting and cooling may have been delayed for 
a time long enough to permit the formation of 
fibrin clots without appreciable effects upon the sep- 
aration, as the following tables t very clearlj^ show, 
the efficiency of creaming being measured by the 
percentage of fat in the skimmed milk: 



*Loc. eit. 

t Cornell University Agricultural Experiment Station, Bull. No. 29, p. 73." 



Effect of Delay in BeejJ Setting System. 101 



Effect of delayed setting upon creaming. 





01 

u 

o 

6 


i 

eg 

U 
1 

P. 

g 


Per cent fat in whole 
milk. 


I. 
Set at once. 


Date, 
1890. 


1 

CO 


cc 

P. 


•2d 
§a 


1. Dec. 24, p. M. . . . 

2. Dec. 25, a. m. . . . 

3. Dec. 25, p. m. . . . 

4. Dee. 26, a. m. . . . 

5. Dee. 26, p. m. . . . 

6. Dec. 26, a. i\i. . . . 

7. Dec. 26, p. m. . . . 

8. Dec. 27, a. m. . . . 


13 

8.5 
12 

9.75 
16 

8.25 
14 

9 


40 

40 

40 

40 

40 

40 ' 

40 

40 


3.90 
3.45 
4.05 

4.10 
4.15 
4.00 
3.90 


35.5 

18.5 

37 

29 

36 


92 

86 
86 
88 
90 


.57 
.56 
.59 
.55 
.24 


Average of all .... 
Average Nos. 1-5 . . . 


11 


40 


3.94 




88 


.50 
.50 





11. 

Delayed— kept warm. 


III. 

Delayed— cooled. 


Date, 
1890. 


1 

cc 


<s 

>> 

S 
"S 

CO 

01 
+J 

60 
45 
45 

130 
75 

205 
90 

210 


p. 

a 
® 


•sd 
s a 


1 


1 

a 


to 

p. 

a 


ii 


1. Dec. 24, p. M. 

2. Dec. 25, a. m. 

3. Dee. 25, p. m. 

4. Dec. 26, A. m. 

5. Dec. 26, p. m. 

6. Dec. 26, a. m. 

7. Dec. 26, P. M. 

8. Dec. 27, A. M. 


24.5 

18.5 

37 

30.25 

36 

37.5 

24 

74 


88 
84 
84 
82 
90 
92 
90 
95 


.59 
.56 
.47 
.68 
.22 
.68 
.49 
.68 


30 

75.5 

61.5 

37.5 
23.5 
74 


00 

220 

60 

205 

90 

210 


68 
62 
74 

58 
65 
64 


.64 
.55 
.53 

.66 
.65 
.51 


Average of all . 
Average Nos. 1-5 
Average ** 6-8 




107 


88 


.55 
.50 
.58 




141 


65 


.59 
.57 
.60 



102 Milk mid Its Products. 

The milk was divided into three portions ; one was set at 
once, one was delayed for an hour, but kept up to a tempera- 
ture of 92 in a water bath, and the third was put in the open 
air and allowed to cool for an hour before set. In the cases 
of delay, the milk was stirred up just before it was placed in 
the creamer, and all the settings were made in Cooley cans, in 
ice water. 

The trials reported under the same number, with the excep- 
tion of the first and second, are comparable, as they were made 
from different portions of the same samples of milk. In num- 
bers 1 to 5, inclusive, the delayed sample (Column II.) was 
kept warm in a water bath ; in numbers 6 to 8 the milk 
used had been carried about on the route, and the delayed 
sample was heated up after having been allowed to cool. 

From a similar series of experiments Jordan* 
concluded : 

That with herds of ordinary size, it will not be profitable 
to submit to any great inconvenience in order to place the 
milk in ice water immediately after it is drawn. In a half 
hour to an hour, milk does not seem to cool sufficiently to ma- 
terially affect the completeness with which cream will rise. 

In order to overcome certain difficulties that often 
occur in raising cream by deep setting process, dilu- 
tion of the milk with water has been recommended, 
usually under one of the three following conditions: 

1st. Dilution with one -fourth to one -third of hot 
water, 135° F., and setting in deep cans at a tem- 
perature as low as can be obtained without the use 
of ice, not below 55°. 

2d. Dilution with one -half to equal quantities of 



* Maine Agr. Exp. Sta. Rept. 1890, Part II. page 48. 



Effect of Dilution in Beep Setting System. 103 

cold water, and setting under the same conditions as 
above. 

Both of these being intended as substitutes for the 
use of ice in cool deep setting in the summer time. 

3d. Dilution with one -third to one -fourth of hot 
water (135°), setting in deep cans in ice water (40 F.). 

This last intended to overcome the difficulty of 
complete creaming often found in the fall and early 
w^inter with the milk of cows far advanced in the 
period of lactation. 

The idea is that the increased fluidity imparted to 
the milk by the water would facilitate the separa- 
tion of the fat globules. During the winters of 
1888-9 and 1889-90 very little ice could be harvested 
through the dairy regions of the northeastern United 
States, and in the summer following this idea of 
dilution was widely advocated and considerably prac- 
ticed ; but experience and experiment* have shown 
that while dilution may be of some advantage w^hen, 
for lack of a supply of ice or other reasons, it is 
not possible to secure a temperature below 60° F., 
it can in no case be considered a satisfactory sub- 
stitute for setting the cans in water at a tempera- 
ture of 40° F. 

The amount of advantage which may be obtained 
where dilution is practiced, as measured by the per- 
centage of fat in the skimmed milk, is seen in the 
following tables (on pages 104 and 105), taken from 
Bulletin No. 39 of the Cornell University Agricultural 
Experiment Station : 



* Vermont Agricultural Experiment Station, 4th Ann. Rept. p. 100. 



104 



Milk and Its Products. 



Diluted and undiluted milk set in ivater at a temperature 

of 60° F. 





!0 


CO 


Temperatures F. 


a 

a 
a 


i 

a 

0) 

u 
O 




Diluted. 


Not diluted. 


Date, 

1892. 


i 




a. 


0) 

3 

i 


S CO 




sa 

P^ 


g <» 

r-l tC 

o . . 


Fel>. 19 . 


54 


18 


84 


135 


97 


65 


60 


12 


4.2 


1.07 


.89 






■ 19 . 


72 




84 




84 


65 


59 


13 


4.2 






1.33 


1.09 


" 22 . 


54 


18 


90 


136 


99 


64 


59.5 


12.5 


4.2 


.52 


.43 






" 22 . 


72 




90 




90 


64 


57.5 


14.5 


4.2 






.97 


.77 


" 23 . 


54 


18 


89 


135 


101 


66 


60.75 


11.25 


4.3 


.80 


.68 






" 23 . 


72 




89 




89 


66 


58.50 


13.5 


4.3 






1.12 


.91 


" 28 . 


54 


18 


88 


134 


98 


57 


58 


14 




.35 


.28 






" 28 . 


72 




88 




88 


57 


57 


15 








.65 


.51 


" 29 . 


54 


18 


86 


134 


97 


60 


59.75 


12.25 


4.4 


.68 


.56 






" 29 . 


72 




86 




86 


60 


58 


14 


4.4 






1,18 


.95 


Mar. 1 . 


54 


18 


86 


135 


96 


60 


61 


11 


4.1 


.68 


.58 






1 . 


72 




86 




86 


60 


58.5 


13.5 


4.1 






.96 


.78 


" 13 . 


54 


18 


86 


135 


96 


60 


60.75 


11.25 


4.3 


.85 


.72 






" 13 . 


72 




86 




86 


60 


57.75 


14.25 


4.3 






.82 


.66 


" 14 . 


27 


9 


84 


136 


96 


58 


29.5 


6.5 


3.9 


.88 


.72 






" 14 . 


36 




84 




84 


58 


30 


6 


3.9 






1.14 


.95 


" 15 . 


27 


9 


86 


132 


95 


58 


30 


6 


3.9 


.73 


.61 






" 15 . 


36 




86 




86 


58 


29.5 


6.5 


3.9 






1.25 


1.02 


" 26 . 


27 


9 


88 


136 


101 


56 


29.5 


6.5 


4.1 










" 27 . 


36 




88 




88 


56 


28.5 


7.5 


41 






.67 


.53 


" 27 . 


54 


18 


90 


135 


100 


64 


60.25 


11.75 


4.5 


.81 


.68 






" 27 . 


36 




90 




90 


64 


30 


6 


4.5 






.70 


.58 


" 28 . 


27 


9 


88 


136 


102 


61 


31 


5 


4 










" 28 . 


36 




88 




88 


61 


30 


6 


4 






1.21 


1.01 


" 31 . 


27 


9 


87 


135 


102 


62 


30 


6 


4.1 


.93 


.78 






" ;5i . 


36 




87 




87 


62 


29.75 


6.25 


4.1 






1.17 


.97 


Apr. 2 . 
^' 2 . 


27 


9 


91 


135 


103 


65 


30 


6 


4.7 


1.08 


.90 






36 




91 




91 


65 


29 


7 


4.7 






1.68 


1.35 


4 . 


27 


9 


92 


135 


102 


62 


29 


7 


4.2 


.31 


.25 






4 . 


36 




92 




92 


62 


29 


7 


4.2 






.92 


.74 


Average 

















.76 


.62 


1.05 


.85 



Effect of Dilution in Beep Setting System. 105 



Diluted and undiluted milk set in tvater at a temperature of 

40° -45° F. 









Temperatures F. 


02 




PI -. 


Diluted. 


Not diluted. 












•-d 




•S^- 


s«" 


Date, 


CO 












1 




=2 a 


•a 


■B^ 




■Sm 


1892. 






M 






03 
i 


a 


a 


§2 


4j V 

n 




4J "^ 


V, s 

o 




54 


18 


87 


140 


-4^ 
<S 

100 


2 

44 








t' 


(2 




rt — — . 


Feb. 20 . 


58 


14 


4.4 


.32 


.26 






" 20 . 


72 




87 




87 


44 


54.25 


17.75 


4.4 






.25 


.19 


" 21 . 


54 


18 


88 


136 


99 


44 


57.5 


14.5 


4.4 


.20 


.16 






" 21 . 


72 




88 




88 


44 


53.75 


18.25 


4.4 






.24 


.18 


" 24 . 


54 


18 


87 


134 


97 


45 


56.25 


15.75 


4.2 


.23 


.18 






" 24 . 


72 




87 




87 


45 


53.5 


18.5 


4.2 






•17 


.13 


" 25 . 


54 


18 


90 


134 


100 


46 


57 


15 


4.4 


.23 


.18 






" 25 . 


72 




90 




90 


46 


54.25 


17.75 


4.4 






.26 


.20 


Mar. 30 . 


27 


9 


86 


135 


100 


44 


29 


7 




.32 


.26 






" 30 . 


36 




86 




86 


44 


27 


9 








.35 


.26 


" 17. 


27 


9 


88 


136 


97 


44 


29 


7 


4.7 


.11 


.09 






" 17 • 


18 




88 




88 


44 


13.5 


4.5 


4.7 






.18 


.14 


" 30 . 


27 


9 


86 


135 100 


44 


28 


8 


5 


.08 


.06 






" 30 . 


18 




86 




86 


44 


13 


5 









.12 


.09 


April 5 . 


27 


9 


90 


138 


103 


46 


29.75 


6.25 


3.3 


.31 


.25 






18 




90 




90 


46 


14.5 


3.5 


3.3 






.28 


.23 


Average 


■ • 


• • 


• • 


• • 












.23 


.18 


.23 


.18 



Summing up all of the experiments, the average 
efficiency of creaming as measured by the percent- 
age of fat in the skimmed milk would appear to be 
about as follows : 

Diluted, set at 60° (39 trials) .77 per cent. 
Undiluted, set at 60° (30 " ) LOO " 
" " 40° (26 " ) .29 " 
It would seem, therefore, that while, when the 
milk is set at 60° F. or thereabouts, there is consider 
able advantage, so far as the efficiency of creaming 



106 Milk and Its Products. 

is concerned, in diluting it with 25 per cent of warm 
water, this dihition cannot be regarded as a sub- 
stitute for setting without dilution in ice water, and 
it has the further disadvantage of requiring in- 
creased tank capacity. 

GentrifugcU separation. — In separating cream in a 
centrifugal machine, the centrifugal force generated 
in a rapidly revolving bowl is made to take the 
place of the force of gravity acting upon the milk 
at rest in a vessel. The amount of force generated 
is so much greater than the force of gravity that 
the separation of the particles of fat is much more 
rapid and much more complete. The force, how- 
ever, acts in a horizontal instead of a vertical direc- 
tion. In 1877, a patent was granted to Le Feldt & 
Lentsch for a machine to separate milk by centrif- 
ugal force. This first centrifugal separator consisted 
merel}' of a series of buckets hung upon arms 
swinging from a central axis. When the machine 
was at rest the buckets assumed a vertical position, 
but in motion they were thrown out horizontally from 
the arms. The milk was placed in these buckets, 
the machine set in motion until the cream w^as sepa- 
rated from the skimmed milk, and when the machine 
was allowed to come to a stand -still the buckets 
assumed a vertical position, and the cream was re- 
moved from the top in the same way that it was 
skimmed from any other vessel. From this was 
evolved a machine consisting of a revolving bowl 
or drum in which the separation takes place, with 
arrangements for removing the skimmed milk and 



structure of Centrifugal Separator. 



107 



cream without stopping the machine, thus making 
the separation continuous. The various parts of 
the machine have been much improved in minor de- 
tails. At the present time the essential parts of 

u 




Fig. 10. Section of separator bowl of plain or "Hollow Bowl" type. 

a separator are the bowl, with or without internal 
devices or arrangements to assist in the separation 
of the cream from the milk, an outlet for the 
skimmed milk, an outlet for the cream, an inflow for 
the whole milk, and the proper mechanical means 



108 Milk and Its Products. 

for revolving the bowl. (The more common types of 
separator bowls are shown in Figs. 10-13.) Usually 
the bowl is di'iven in an upright position, but there 
are separators in which the bowl is driven in a hori- 
zontal position, and in the greater number of ma- 
chines the w^alls of the bowl are cylindrical. In the 
process of separation the milk flows into the bowl, 
and, partaking of the centrifugal force, is forced to 
the extreme outer edge of the bowl. As the milk 
continues to flow in, the bowl begins to fill from 
the outside toward the center. The centrifugal force 
acting more strongly upon those parts of the milk 
which have the greatest specific gravity, they are 
thrown to the extreme outside, and the lighter por- 
tions, the fat globules, with whatever may adhere 
to them, are forced to the center. Attached to the 
extreme outer edge of the bowl are one or more 
tubes, which, bending inward along the side of the 
bowl, find an opening near the center. These are 
the outlets for the skimmed milk. From the ex- 
treme center of the bowl, also leading to the out- 
side, is the cream outlet. When the bowl becomes 
filled with milk, the centrifugal pressure will force 
out through the skimmed milk outlets the milk nearest 
the outside of the bowl. These outlets are made 
of such size in comparison with the size of the bowl, 
the speed of the machine, and the size of the inflow 
tube, that they have a capacitj^ of discharging the 
milk from .4 to .9 as fast as it runs in ; the remain- 
ing contents of the bowl are then forced toward 
the center, and find an exit through the cream 



Theory of Centrifugal Separation. 109 

outlet. In this way the milk as it enters is divided 
into two portions : one, the larger, drawn from the 
extreme outer portion of the bowl, consisting of 
skimmed milk, and the other, the smaller, escaping 
from the center of the bowl, the cream. A third 
portion also usually accompanies centrifugal sepa- 
ration. A part of the semi -solid constituents of 
the milk, being heavier than the milk serum, are 
thrown to the outside of the bowl, and adhere to 
the walls in the form of a creamy or gelatinous mass, 
which is ordinarily called separator slime. It consists 
mainly of albuminous matters with some fat globules 
adhering, and any particles of dirt or foreign mat- 
ter that may be mechanically mixed with the milk. 
It varies greatly at different times and seasons. 
Usually the amount is not large, but not infrequently 
it is sufficient to clog the outlets of the separator after 
a run of an hour or two. The separator slime is 
largely composed of matter deleterious to the qual- 
ity of cream and butter, and its removal is to a 
great extent a purification of the cream. The various 
conditions affecting this operation are as follows : 

Conditions affecting the completeness of separa- 
tion. — The completeness of the separation is depend- 
ent upon the centrifugal force generated, the rate 
of inflow, the temperature of the milk, and the 
physical condition of the milk. 

The amount of centrifugal force generated depends 
upon the diameter of the bowl and the velocity of 
rotation. 

Roughly speaking, the centrifugal force increases 



110 Milk and Its Products. 

directly in proportion as the diameter is increased and 
directl}^ with the square of the velocity. The larger 
the bowl, then, and the greater the speed, the greater 
the centrifugal force and the more complete the sep- 
aration. The rate of inflow of milk affects the 
separation, because the separation is more complete 
the longer the milk is subjected to the centrifugal 
force, and the slower the milk flows into a given- 
sized bowl the longer any particle will be in flowing 
through it and the more completely will the cream 
be separated. The temperature of the milk affects 
the fluidity of the fat globules and their ease of mo- 
tion upon the other particles of the milk; the warmer 
the milk the more easilj^ are they separated. A 
temperature of 76° to 98° F. is the one commonly 
emploj^ed because of the effect upon the texture of 
the butter. It is desirable that the milk should be 
separated at as low a temperature as possible without 
interfering with the completeness of the separation, 
so that, other things being equal, that separator is the 
best that separates the milk at the lowest tempera- 
ture. The physical condition of the milk affects 
separation by the centrifugal in the same waj-s that 
gravity creaming is affected, but to a very much 
slighter degree. Small -sized fat globules, viscosity 
of the milk, and coagulation of part of the casein 
by incipient fermentations, all tend to make separa- 
tion more difficult ; but in a majority of cases, un- 
less the milk is so sour as to be coagulated, it may 
be completely creamed with a centrifugal separator, 
but will require a slower feeding (a reduction of 10 



Relative Amount Skimmed Milk and Cream. Ill 

to 15 per cent will usually suffice), and a higher speed 
of the bowl, or both. 

Conditions affecting the relative amount of skimmed 
milk and cream. — The relative amount of skimmed 
milk and cream is affected by the rate of inflow, 
bj' the speed of the bowl, by various special con- 
trivances upon the machines themselves, and to a 
slight extent by the temperature of the milk. In 
the ordinary machine the size of the skimmed milk 
outlet is fixed, and therefore at a given velocity the 
outlet will discharge a nearly uniform quantity of 
fluid. If, then, the milk is turned into the bowl at 
such a rate that .8 of it escapes through the skimmed 
milk outlet, we shall have .8 skimmed milk and 
.2 cream. If now we reduce the rate of inflow 
by .1, we shall get just as much skimmed milk as 
before, but only one -half as much cream ; or if the 
inflow is increased by . 1 , we shall get the same 
amount of skimmed milk and once and a half as 
much cream. If under the first conditions all of the 
fat was gathered into the cream, we shall have just 
as complete a separation as before, but will simply 
get a cream containing a greater or less percentage 
of fat, provided that the increase of inflow has not 
increased the total amount above the capacity of the 
machine. In other words, the greater the inflow, 
the more cream and the thinner the cream ; the 
smaller the inflow, the less cream and the richer the 
cream. These variations can only take place within 
comparatively narrow limits. If we increase the in- 
flow too much, we shall soon reach a point at which 



112 Milk and Its Products. 

the milk passes so rapidly through the machine that 
the separation is not complete, and if we reduce the 
inflow to such a point that the skimmed milk outlet 
has a capacity of discharging the milk as fast as it 
flows in, w^e shall get a separation until the bowl 
becomes filled, and then all of the milk will pass 
out of the skimmed milk outlet in the same condi- 
tion in which it enters the machine. 

The speed of the machine, also, affects the rela- 
tive amount of cream and its percentage of fat. The 
size of the skimmed milk outlet being fixed, the 
faster the bowl is revolved the greater the capacit}^ 
of this outlet will be, so that, the rate of inflow 
remaining uniform, the faster the bowl is revolved 
the less proportional amount of cream we shall have, 
and the richer it will be in fat, and vice versa. It 
must be borne in mind, further, that the speed of 
the bowl is also an important factor in the complete- 
ness of separation, and that if the speed is slackened 
in order to get a greater bulk of cream, there will 
be danger of incomplete separation. 

Most of the machines have arrangements for reg- 
ulating the relative amount of skimmed milk and 
cream without changing the rate of inflow or the 
speed of the machine. In most of the machines 
this arrangement is known as a "cream screw," and 
affects the amount of cream by placing the cream 
outlet nearer or farther from the center of the bowl; 
the nearer the center the cream screw is turned, the 
thicker will be the cream and the smaller the amount. 
Some of the separators change the proportion of 



Modifications in Structure of Bowl. 



113 



cream by increasing or decreasing the capacity of the 
skimmed milk outlet. If the capacity of the skim- 
med milk outlet be decreased, necessarily the amount 
of the cream will be increased, and vice versa. 

The temperature of the milk only slightly affects 
the proportion of skimmed milk and cream. The 
warmer the milk, the more fluid it is, and the faster 
it will pass through the various openings of the ma- 
chine. Slightly more milk at 85° will run through 
the same inflow than at 70°, and a large part of 
this increase will be found in the cream. The 
pressure of the milk in 
the vat above the ma- 
chine will materially af- 
fect the rate of inflow, 
and a few inches w411 
make a difference of 
two or three hundred 
pounds per hoar on a 
large -sized machine. 

Contrivances in the 
howl to increase the ef- 
ficiency of sex)aration. — 
In the fli'st separators 
made, the bowl was 
hollow, and the separa- 
tion was caused directly 
by the centrifugal pres- 
sure acting upon the 
milk in a mass. In 
the later machines, va- 




Fig. 11 



Section of separator bowl of 
the disc or "Alpha" type. 



114 



Milk and Its Products. 



rious contrivances have been introduced in the bowl 
to aid in the completeness of the separation or to 
increase the capacity. These contrivances have been 
of two general types : one to break up the wall of 
milk, and so give the particles of milk and cream 
a better chance to pass by one another in their 
passage from the center to the outside of the bowl; 
the other, a series of interruptions to the passage 

of the milk from 
its entrance 
at the center 
to the outside, 
causing it to 
travel a much 
greater dis- 
tance and be 
subjected to the 
centrifugal force 
for a longer 
time. These 
contriva n ces, 
while adding to 
the complexity 
of the machine, 
have increased 
the capacity 
and theeffi- 
ciency of the 
separation. The best known of these contrivances 
are the so-called "Alpha" discs or plates, — a series 
of cup -shaped plates, nearly filling the bowl of the 




Fig. 12. Section of separator bowl of "United 
States " type. 



Meclianical Conditions Affecting Separation. 115 

separator. These Alpha plates nearly doul)le the 
separating capacity of the hollow bowl of the same 







Fiy. i:i. Parts of bowl of "United States" type. 

diameter, and at the same time the efficiency of sep- 
aration is increased. 

Mechanical conditions which affect separation. — Cer- 
tain pecnliarities in the construction or operation of 
the machine often materially influence the efficiency 
of separation. One of the most important of these 
is that the bowd should run steadily and smoothly, 
without any perceptible jar or trembling. The trem- 
l)ling of the bowl may be caused by lack of per- 
fect balancing in the bowl itself. This can only be 
remedied by the manufacturer. The bowl may trem- 



116 MilJi iuid Its Products. 

ble, also, because the bearings are not perfectly ad- 
justed ; and, lastly, tlie bowl may tremble because 
the machine is not set level or upon a solid founda- 
tion. A second cause of inefficient separation is 
variation in the velocity of the bowl. It is quite as 
important that the bowl run uniformly as it is that 
it attain any given rate of velocity. In this re- 
spect the turl^ine separators are more likely to be 
at fault than those run by belt power, and separa- 
tors turned by hand are more subject to variations 
than those run l\v power. 

An engine of ample power, with a good gover- 
nor, and the power transmitted through an interme- 
diate rope belt kept perfectly tightened, with well-oiled 
bearings all around, are the best safeguards to uni- 
form speed. 

Efficiency of scparotion in centrifugol ntorhincs. — 
With the centrifugal separator run under perfect con- 
ditions, there is still a slight loss of fat in the 
skimmed milk. This need not be greater than .1 
of 1 per cent. At the present time it is considered 
that where more than .1 of 1 ])cr cent of fat is left 
in skimmed milk, a centrifugal machine is not doing 
perfect work, and numerous trials have shown that 
the machines of the leading forms can be made to 
reach this point of efficiency, as may be seen from 
the following table, ''' giving the average of a large 
number of tests made hy several agricultural experi- 
ment stations : 



* Cornell University Agricultural Experiment Station, Bulletin No. 105. 



Eddtivc Effiri(')i(U of 8ep(ir<it(})-s. 



117 





Per cent of fat in skimmed milk. 




Average. 






Name of macMue. 








By 


series. 


Of all 
trials. 

.11 


Minimum. 


^laximiim. 


Aeeumiilator . . 


12 


.01 


.20 


Alexandra Jumbo . . 


22 


.22 


.15 


.33 


Columbia . . 


09 


.12 


.05 


.34 


Danish Weston . . . 


10 


.08 


.01 


.25 


DeLaval 


13 


.09 


.01 


.50 


Sharpies ... 


27 


.16 


.05 


.65 


United States .... 


18 


.12 


.01 


.60 


Victoria 


21 


.16 


.05 


.38 



A series of trials made in Germany* shows a con- 
siderable variation in the various styles, and, on the 
whole, a rather less efficiency than has been obtained 
in this country, as is seen in the table following : 



Name of machine. 


Revolutions 
of bowl 
per min- 
ute. 


Pounds 
separated 
per hour. 


Tempera- 
ture of 
milk F. 


Per cent 

of fat in 

skimmed 

milk. 


Number 
of trials. 


Alpha B • • • 


5,100 


537 


92 


.23 


37 


Alpha Baby . . 


6,900 


286 


72 


.23 


23 


Baby 


6,360 


129 


88 


.18 


15 


Victoria . 


• • 


205 


92 


.17 


19 


Small Danish . 


7,241 


288 


90 


.28 


16 


Large Danish . 


7,217 


411 


91 


.35 


16 


Adjustable . . . 


8,640 


363 


70 


.10 


3 


Arnold's . . . 


8,531 


458 


90 


.28 


26 


Medium Brown 


4,037 


268 


91 


.37 


16 



But while all the forms of separators can be made 
to do perfect work, there is more or less variation 



* Milch Zeitung, xxiii,, p. 296- 



118 



Milk and It^ Products. 



in the work done by the different machines of the 
same style and manufacture. This variation is due 
to slight peculiarities in the construction of the in- 
dividual bowls, and which cannot be detected by 
the ordinary senses, and only appear upon an ex- 
amination of the skimmed milk after actual use. 
These differences are well illustrated in a series of 
trials made in different factories,^' and shown in 
detail in the following tables: 



ALEXANDRA JUMBO. 

Bated capacity, 2,000 pounds per hour. 







Pounds 






Average 




Pounds 






No. 


of 


Average 
temper- 


Range 


speed of 


Range 


sepa- 


Per cent 


Date. 


of 


milk 


of 


bowl, 


of 


rated 


of fat in 




fac- 


in whole 


ature. 


temper- 


revolu- 


speed. 


per 


skimmed 




tory. 


run 




ature. 


tions per 




hour. 


milk. 




7 




70 




minute. 




1,344 




Aug. 19. 


3,809 


66-75 7,200 


7,000-7,400 


.25 


" 20. 


8 




70 


68-72 


6,985 


6,800-7,200 1,170 


.15 


" 20. 


8 




70 


68-72 


6,585 


6,300-6,900 


1,611 


.20 


" 21. 


9 


5,928 


75 


72-81 


6,900 


6,600-7,100 


1,882 


.20 


" 23. 


11 


4,052 


84 


80-86 


6,600 


6,200-7,400 


1,814 


.33 


Average 






74 




6,854 




1,564 


23 











DE LAVAL, ALPHA NO. 1. 

Bated capacity, 2,500 pounds j;er lioiir. 



July 17. 


3 


2,519 


80 


78-85 


5,520 


4,800-6,100 


2,606 


.08 


Aug. 18. 


6 


3,629 


74 


73-76 


5,806 


5,700-6,000 


2,592 


.05 


Sep. 16. 


17 


1,187 


72 


71-73 


5,933 


5,800-6,000 


2,456 


.08 


"^ 20. 


22 


4,627 


82 


80-83 


6,071 


5,800-6,200 


2, .501 


.04 


" 21. 


23 


6,376 


78 


77-80 


6,041 


6,000-0,200 


2,.500 


.03 


Oct. 4. 


24 


5,588 


82 


78-85 


5,844 


5,600-6,000 


2,747 


.13 


" 4. 


25 


1,802 


86 


85-90 


6,280 


6,000-6,400 


2,040 


.03 


Average 




79 


.... 5,928 




2,491 


06 


1 





* Cornell University Agi-icultural Experiment Station, Bulletin No. 105. 



Variations in Machines of Same Style. 119 



DE LAVAL, BABY. 

Bated capacity, No. 2, 350; Xo. 3, 600 poumls per hour 



Date. 


No. 
of 
fac- 
tory. 


Pound s 

of 

milk in 

whole 

run . 


Average 
temper- 
ature. 


Range 

of 
temper- 
ature. 


Average 
speed of 
bowl, 
revolu- 
tions per 
minute. 


Range 

of 
speed. 


Pounds 
separ- 
ated 
per 
hour. 


Per cent 

of fat in 

skimmed 

milk. 


May 31. 

Sep. 14. 

'^ 18. 


1 
14 
19 


20.-; 

146 


96 
83 




Rev. crank 
.34 
46 
46 




:{62 
303 


.0;") 
.06 
.16 


81-86 


Average 






90 


49 




333 


.09 



DE LAVAL, STANDARD. 

Rated capacity, 1,100 jyounds per hour 



Sep. 19. 
" 19. 
" 19. 


21 
21 
21 


— 


73 
73 
72 


71-75 
71-75 
71-75 


Rev. bowl 
7,914 
8,140 
8,300 


7,700-8,200 
7,600-8,400 
8,000-8,500 


1,020 

930 

1,000 


.25 
.15 
.10 








73 




8,118 


983 .19 













SHARPLES RUSSIAN. 

Bated capacity, Standard, 1,100 pounds ; Imperial, 2,000 pounds 

per liour. 



July 16. 


o 




84 


83-87 


7,775 


7,700-7,900 


2,100 


.40 


July 16. 


9 





88 


87-88 


7,183 


7,000-7, .500 


2,130 


.65 


Aug. 17. 


5 


1,718 


80 


78-82 


7,800 


7,700-7,900 


1,874 


.10 


Aug. 24. 


12 


4,028 


81 


80-82 


7,700 


7,100-8,300 


1,033 


.05 


Sept. 14. 


13 


2,509 


85 


84-86 


7,433 


6,800-7,600 


1,1.58 


.13 


Sept. 17. 


18 


3,. 562 


87 


82-95 


7,558 


7,200-7,900 


1,752 


.45 


Oct. 6. 


18 


2,716 


90 


87-91 


7,675 


7,400-7,900 


1,873 


.38 


Average 

1 






85 




7,589 




1,703 


.31 



UNITED STATES. 

Bated capacity, 2,000 pounds per hour 



July 18. 
Aug. 22. 
Sept. 15. 
Sept. 15. 
Sept. 18. 

Average 



4 
10 
15 
16 
20 



3 962 
1,870 
3,850 
2,902 



83 
81 
94 

88 
78 

85 



82-84 

79-91 

90-98 

8)-100 

77-80 



7,120 

7,025 
7,600 
6,075 
6,.586 

6,881 



7,000-7,200 
6,800-7,300 
7,200-8,000 
5,600-6,600 
6,400-6,800 



2,220 
1,964 
1,403 
1,650 
2,176 

1,883 



.18 
.25 
.08 
.38 
.60 

.30 



120 Milk and Its Products. 

These slight differences in individnal bowls are 
common to all of the different kinds of machines, so 
far as is known, and this being the case, it is al- 
ways dne to the pnrchaser that he shonld sc^cnre from 
the manufacturer a guarantee that any given ma- 
chine will do work of a certain grade of efficiency. 

Other desirahle and undesirahJe features of a sepa- 
rator. — Other things being equal, that separator is the 
best which will skim clean at the lowest temperature 
and with the least numlier of revolutions per min- 
ute. Other details of construction being equally 
good, and the capacities being the same, that separator 
will run the easiest whose diameter is least. A ma- 
chine of small diameter not only runs easier, but is 
less easih- thrown out of balance. The cream should 
be delivered in a smooth stream of uniform density, 
and the cream outlet should be of such form that 
a heavy cream may pass through it without danger 
of clogging. The bowl should be so constructed that 
all parts may he readily reached with the hand and 
thoroughlv and easilv cleaned. 



CHAPTER VII. 

THE RIPEXIXG OF CREAM. 

By the ripening process is meant all the treatment 
Avhicli the cream receives from the time that it is sep- 
arated from the milk until it is put into the churn. 
Upon this treatment, and the changes that the cream 
undergoes, very largely depend the quality of the butter 
as regards texture and flavor. The texture of the 
butter is very largely influenced by the changes of tem- 
perature that are brought about during the ripening 
process. It seems to be essential to the production of 
a firm, solid texture in the butter that the cream, at 
some time during the ripening process, should be sub- 
jected to a constant temperature below 50° F. for sev- 
eral hours. When cream has been separated by a 
gravity process, particularly by a "deep setting" one, 
it has already experienced the effects of such a tem- 
perature, and is read}' for ripening as soon as re- 
moved from the milk. But when cream is separated 
by a centrifugal separator, the temperature as it comes 
from the separator is rather high, and butter of good 
texture cannot be made unless the cream is cooled 
down and held cool for several hours before ripening 
has far advanced. The first step, then, in the ripen- 
ing process with separator cream is to reduce its 

(121) 



122 Milk and Its Products. 

tempei'ature as rapidly and as uiiiformlj^ as possible 
to at least 50° F., and to hold it there for as long 
a time as is convenient, usually six to eight hours. 
Another point which influences the texture of the 
butter depends upon the rapidity with which the vari- 
ous changes of temperature are made, and the ex- 
tremes of temperature that are used. That butter will 
have the best texture which has seen the fewest pos- 
sible changes of temperature between the time the milk 
is drawn from the cow and the time it is churned, 
and in which also all the necessary changes of tem- 
perature have been made most gradually. Not only 
will such butter have the best texture at low tem- 
peratures, but it will stand the effects of high tem- 
peratures better. In other words, it " stands up " 
under the heat better than butter that during the pro- 
cess of manufacture has been subject to sudden and 
great changes of temperature, although the final result 
may have been to keep it at a low temperature. 
The effects of ripening are more important and more 
marked upon the flavor of the butter than upon the 
texture. It is during the ripening that the charac- 
teristic flavors of the butter are largely brought out. 
It is not necessary to the manufacture of the butter 
itself that the cream be ripened at all. Butter may 
be made from cream just as soon as it is separated 
from the milk, but it will be of a distinctly different 
quality from that made from ripened cream. By 
ripening in the ordinary sense is meant the produc- 
tion of lactic acid in the cream. 

In some attempts to substitute other acids for 



Oriyin of Butter Flavors. 123 

lactic acid in ripening", Tiemann^' found that in cream 
to which a small amount of hydrochloric acid had 
been added there was no difficurty in churning the 
butter, that the general flavor of the butter was 
good, but that it lacked in aroma and had a some- 
what oily texture . 

There is some doubt as to the origin of the 
characteristic flavors which are developed in the cream 
during the ripening process. These flavors are un- 
doubtedly due to the presence of certain volatile sub- 
stances — fats, bacterial products, or ether -like com- 
pounds — which are formed during the ripening pro- 
cess. It was formerly supposed that the production 
of the characteristic flavors was almost wholly a pro- 
cess of oxidation, and that cream, in order to be prop- 
erly ripened, and to develop the best flavors, must be 
supplied with an abundance of oxygen in pure air 
during the process. Our knowledge of the presence of 
germs in milk and cream and the effect of their 
growth upon the various constituents of the milk, has 
led us to modify these views. At the present time it 
seems probable that the growth of germs which pro- 
duce lactic acid has much to do with the production 
of the characteristic flavors of ripened cream. It has 
been asserted l)y some, notably Conn, that the produc- 
tion of the flavors is due to the growth of specific 
flavor -producing germs that are largely independent of 
the formation of lactic acid, but this view does not 
seem to explain all of the phenomena of the appear- 

*MiJcli Zeitung, xxiii p. 701. 



124 3Iilk and Its Prodttcfs. 

ance of such flavors, and it is by no means certain 
that the flavors are not in part produced as the result 
of direct oxidation. It is found in practice that the 
regulation of the production of lactic acid is the 
chief means in controlling' the flavor. 

The means of 2)rodiicing lactic acid. — In order that 
the milk or cream should ripen, or become sour, it 
is necessary that germs of lactic acid fermentations 
should gain access to it, and that a temperature favor- 
able to their normal development should be secured. 
The presence of the germs niaj' be left to chance 
inoculation, or they may be artificiallj" supplied. 
Under ordinarj^ conditions, by the time the cream has 
been separated from the milk, there will have reached 
it a sufficient number of germs of fermentation to 
cause a rapid production of lactic acid, though the 
number will varj^ from day to day and from time to 
time, and a certain amount of acid cannot be de- 
pended upon within any given specified time. The 
inoculation is more certain, and the desired degree 
of acidity will be more surely reached, at the end 
of a given time, if the germs are added in suffi- 
cient quantity artificially. The source of the inocu- 
lation may be buttermilk or cream from preceding 
churnings, or it may be in the form of an artificially 
prepared "starter" of sour skimmed milk, or it may 
be in the form of any of the so-called commercial 
lactic ferments. It is desirable that none but the 
proper germs should find access to the milk, and 
in relying upon natural means there is always more 
or less danger that putrefactive and other undesirable 



s 



Comniercial Lactic Ferments. 125 

ferments rnaj' gain access to the cream. As between 
tlie various forms of artificial starter, there is not 
much to be said. It is generally held that a starter 
made from skimmed milk is less likely to contain 
germs other than those desired than when cream, 
whole milk, or even buttermilk are used. 

With regard to the use of the various commer- 
cial bacterial ferments, there is considerable diversity 
of opinion. Their use was first recommended several 
years ago in Denmark, as a result of the researches 
of Storch, and has grown rapidly, both in Denmark 
and Germany, until at the present time a large part 
of the butter produced in the former country is made 
from cream first pasteurized, and then ripened with 
the aid of an artificial bacteria culture. The use 
of such ferments has only slightly extended to this 
country, chiefly through the medium of Hansen's 
lactic ferment. 

In this countrj^ Conn has lieen the chief investi- 
gator of similar organisms. From 1890 to 1893* he 
isolated several organisms, the culture of which in 
cream improved the flavor of the resulting butter 
to a greater or less extent. In the latter year he 
discovered in a can of milk sent from Uruguay to 
the World's Columbian Exposition at Chicago, a 
germ so much better in this respect that it alone 
has since been used, and cultures of it placed upon 
the market under the name of B.41 (Bacillus No. 41). 

A series of investigations by Farrington and Rus- 



*Storrs Agrienltural Experiment Station, Reports 1890-93. 



126 



3Iilk and Its Prodiccts. 



sell,* in which a large number of samples of butter 
were made from cream ripened by the use of B. 41, 
and in the ordinary way, or " normall}," and sub- 
mitted to the judgment of several experts who were 
ignorant of the process of manufacture, led to the 
conclusion that the "Conn culture, B. 41, did not 
improve the flavor of the separator butter ripened 
for one day at a high temperature, or of that ripened 
for a longer time at a lower temperature ; on the 
contrary, the score of the fresh B. 41 butter by 
the different judges Wcis, in the majority of cases, 
materially lower than that of normal butter. ''^ * * 
With separator butter in cold storage, that made with 
B. 41 deteriorated less than did the normal butter. 
When taken from storage there was but little differ- 
ence in flavor between these two butters, although 
the normal butter when fresh scored higher." 

The difference in the flavor of the two kinds of 
butter when fresh, as indicated by the different 
judges, is shown in the table: 



Number of butter packages 
scored 

Average score of normal but- 
ter 

Average score of B. 41 butter. 

Difference in favor of normal 
butter . 



Gurler. 


Barber. 


Moore. 


14 

44.4 
- 43.7 


14 

45.3 
44 


12 

45.1 
43 


.7 


1.3 


2.1 



General 
average 
scores. 



45.3 
43.9 



1.4 



*Wisconsin Agricultural Experiment Station, Bulletin 43. 



Temperature of Bipening. 127 

On the other hand, a considerable number of fac- 
tories in this country have secured an increased flavor 
and quality in their product from ripening' their 
cream with the aid of either Hansen's ferment or B. 41. 

The present status of the whole matter seems 
to be that the various commercial artificial ferments 
are now prepared in such form that thej' are readily 
transported, they retain their vitality for a consider- 
able length of time, and are practically free from 
any undesirable germs. Their use in careful hands 
is likely to be followed with uniformly good results. 
Still, where all of the surroundings are cleanly and 
the atmosphere pure, the use of such artificial germs is 
not necessary to produce butter of the highest quality. 

Temperature of ripening. — The various germs of 
lactic fermentations find their o])timum growth point 
at from 80° to 90° F . , and milk or cream kept at those 
temperatures will most rapidly become sour. The 
effect of such high temperatures, while favorable to 
the production of lactic acid, is less favorable to 
the texture of the butter, and on this account it is 
desirable to ripen the cream at as low a tempera- 
ture as will insure a fairly rapid growth of the lactic 
germs. A temperature of from 60° to 70° F. will 
ordinarily luring this about. The amount of acid de- 
veloped in any given length of time will depend not 
only upon the temperature at which the cream has 
been kept, but also upon the number and activity of 
the germs originally present, so that if we have a 
thorough inoculation to start with, a lower temper- 
ature will be sufficient to cause the development of 



128 Milk and Its Products. 

the requisite amoimt of acid ; but if only a slight 
inoculation is present, a higher temperature will be 
necessary. Ordinarily, there will be more germs 
present in the atmosphere during the warm months 
than in the winter, consequently a lower temperature 
will bring about the same degree of acidity in a 
shorter time in summer than in winter. 

The amoimt of acid necessary. — The amount of 
acid that it is desirable to have in the cream at 
the time of churning depends, of course, largely upon 
the flavors desired b}^ the consumer. It is important 
that whatever amount is desired should be uniform 
from day to day. By far the larger proportion of 
consumers prefer the flavors that are characteristic of 
ripening till sufficient acid to slightly coagulate the 
casein is present. Consumers of delicate taste 
readily distinguish between the flavors due to a 
greater or less amount of acid, and it is highly de- 
sirable that some means of determining the amount 
of acid present be available. The butter -maker of 
trained senses has little difficulty in distinguishing by 
the somewhat thickened and glistening appearance of 
his cream, when stirred, the proper condition of the 
cream for churning. Besides this, there are, fortunately, 
more exact means for determining the aciditj*. 

Acid tests. — Dr. A. G. Manns first suggested the 
use of an alkali of known strength to determine the 
proper acidity' of cream for churning, and devised 
what is known as Manns' acid test. It simply con- 
sisted in neutralizing the acid in the cream with a 
standard alkali, the standard used being that known 



Determination of Lactic Acid. 129 

to chemists as deciiiormal, or "i^, and tlie acidity was 
reckoned in terms of cubic centimeters of alkali re- 
quired to neutralize the acid in a given quantit}^ of 
cream. In the use of this test, an indicator which 
changes color according as the medium is acid or 
alkaline, is used. A convenient indicator is phenol- 
phthalein, Avhich is colorless in acid solutions and 
pinkish in alkaline. Later, Professor Farrington* 
devised tablets containing a known amount of alkali 
for the same purpose, known as Farrington's alkaline 
tablets. Each tablet contains an amount of alkali 
equal to 3.8 cubic centimeters of decinormal alkali, 
and a sufficient amount of phenolphthalein indicator. 
The cream to be tested is measured, and to it is 
added a solution of the tal)lets (one tablet in ten 
cubic centimeters of water) until the cream retains a 
pinkish tinge. The tablet solution should always 
be fresh, not more than ten hours old. The tab- 
lets themselves will keep indefinitely. The proper 
degree of acidity is indictated when 30-3'") c. c. of 
Farrington tal)let solution, or 11-13 c. c. of deci- 
normal alkali, are required to neutralize the acid in 
20 cubic centimeters of cream. 

Determination of lactic acid in milk or cream. — Far- 
rington's alkaline tablets may also be conveniently 
used to determine the percentage of lactic acid in any 
given sample of milk or cream. In order to do this, 
it is only necessary to understand that equal volumes 
of normal or decinormal acids and alkalies neutral- 



Bull. 32, 111. Agr. Exp. Sta. Bull. 52, Wis. Agr. Exp. Sta. 



cc 



^! 



130 Milk and Its Products. 

ize each other ; and, further, that a normal sohi- 
tion of hictic acid contains 90 grams of acid in 
each liter, or 1,000 c. c. A decinormal solu- 
tion would contain 1-lOth as much, or 9 grams 
in each liter, and a cubic centimeter would con- 
tain i;^oth as much as a liter, or .009 grams 
of lactic acid. Each tablet of the Farrington 
alkali is equal in strength to 3.8 c. c. of de- 
cinormal alkali, and if the tablet solution is 
made by dissolving 10 tablets in 100 c. c. of 
water, each cubic centimeter of the solution will 
be equal to .38 c. c. of decinormal alkali, and 
will, therefore, neutralize .38 of .009 grams, or 
.0031 grams, of lactic acid. 

To determine the percentage of acid in any 
given sample of milk or cream, a certain 
amount, as 20 c. c, of the sample to be tested 
is measured out, and the tablet solution is ad- 
ded from a burette or graduated cylin- • ■=> 
der till the milk retains a pinkish tinge. 
If this occurs when 1 c. c. of the tablet 
solution has been added, the 20 c. c. 

Fig. 14. . . 

B u- of milk contani .0031 grams of lactic 
acid; but 20 c. c. of milk weigh 20.64 
grams (sp. gr. milk, 1.032), therefore the per- 
centage of lactic acid is .0031 ! 20.64=.00017, 
or .017 per cent. If more than 1 c. c. of 
the tablet solution is required to neutralize 
the acid, or if more or less than 20 c. c. * - 

of milk or cream are taken, the percentage oraiiua- 
of acid will be found by multiplying the cylinder. 



I 

cc. 

62»F. 

!DJ-g-0 
30-i-!3 
30:4 

7a-gno 

50-8-50 
HD-J-SO 

20^80 

ioIBjo 



Further Effects of Ripening. 131 

number of cubic centimeters of tablet solution re- 
quired hy .0034 and dividing by the number of 
grams of milk taken (grams of milk^c. c. X 1.032). 

Further effects of ripening. — Besides affecting the 
flavor, it is believed that ripening aids in the ease of 
churning, in the completeness of churning, and in 
improving the keeping quality of the resulting butter. 
It was formerly supposed that sweet cream could not 
be churned into butter, and in fact with but a moder- 
ate percentage of fat (15 to 20 per cent) it does 
churn with much more difficulty than the same cream 
after it has been ripened ; but since the introduction 
of the separator, and the consequent production of 
a much heavier cream, it has been found that sweet 
cream can be churned into butter quite as readily 
as ripened cream. In cream containing but a 
moderate amount of fat, it is necessary to reduce the 
temperature from six to eight degrees, in order to 
churn it sweet. The difference in the keeping 
quality of ripened and sweet cream butter is like- 
wise not so great as it was formerly supposed to be. 
In fact, sweet cream butter, if properlj' made and 
kept, will in a short time very closely approach the 
qualities of ripened cream butter. 

Effects of churning cream of different degrees of 
ripeness. — If parcels of cream of different degrees 
of ripeness are mixed together and then churned, it 
will be found that the different creams will churn 
differently. One will produce butter in a shorter 
time than another, or with less agitation. The con- 
sequence is that when this occurs the churn is 
J 



132 Milk and Its Products. 

stopped before the churning' is completed, and much 
fat is lost in the buttermilk. It is a matter of 
considerable practical importance, so far as loss of 
fat is concerned, and to some extent also upon the 
flavor of the butter, that all of the cream churned 
at one time should be ripened together, evenlj^ and 
uniformly. If creams of different ages are to be 
churned together they should be mixed together at 
least twelve hours before churning, so that the con- 
dition of acidity shall be the same throughout the 
whole mass. 

Bad effects of over -ripening. — When too much lactic 
acid is developed in the cream the casein is firmly 
coagulated, and in the process of churning is broken 
up into minute granules, which become incorpo- 
rated into the butter in the form of white specks or 
flakes of casein. Such white specks, besides injur- 
ing the appearance of the butter, greatly detract 
from its keeping qualities, as the putrefactive fer- 
mentations soon set up in them and give rise to 
disagreeable flavors. Danger from this source is 
liable to be present if the coagulation of the cream 
has gone so far that any whey has separated. The 
cream should in all cases be churned before the ripen- 
ing process has reached this point. It was formerly 
supposed, and is still generall}' believed, that the pro- 
duction of an excess of lactic acid in ripening tends 
to a loss of butter, from the fact that the acid 
dissolved or "cut" the fat, causing it to disappear. 
This has been shown, both theoretically and practi- 
cally, not to be the case. Lactic acid has no appre- 



Effects of Over - Eijyening . 133 

ciable effect upon fat, so far as dissolving or decom- 
posiug* it is concerned, and cream may be held until 
the whey has separated to the full extent without 
any loss in the amount of l:>utter that it is possible 
to churn from it. The chief evil effect in over- 
ripening is in the production of strong and undesir- 
able flavors accompanj'ing the undue production of 
lactic acid. 



CHAPTER YIII. 

CHURNING. 

The process of causing the particles of butter fat 
to unite into masses, so that they may readily be 
separated from the milk serum, is called churning. 
Such union of the particles of fat is ordinarily 
brought about by agitation of the cream in a suit- 
able vessel, called a churn. If milk or cream be 
agitated at a temperature somewhat below the melt- 
ing point of butter fat, the particles of fat, as they 
pass by one another, agglutinate themselves into 
masses, and, the process being continued, the first 
formed masses continue uniting, until finally the 
whole body of fat may be brought together in a prac- 
tically solid mass. The conditions influencing the 
separation of fat in this way are, first, the viscosity 
of the milk ; second, the ripeness of the cream ; 
third, the nature of the agitation ; fourth, the qual- 
ity of the globules of fat. 

The viscosity of the milJi. — The viscosity of the 
milk affects the churning, in that it tends to keep 
the particles of fat from moving freely upon one 
another, and in that the viscous portions of the 
milk, notably some of the albuminous matter, form a 
more or less dense layer about the fat globules, 

(134) 



Teiiij}er((t({re of Chu)nhi<j. 135 

tending" to keep them apart. The more viscous the 
milk, then, the greater the difficulty with which it 
will churn. 

The ripeness of the cream. — The ripeness of the 
cream affects the churning, largely because of its 
effect upon the viscosity of the milk. The produc- 
tion of lactic acid in milk always has the tendency 
to render it less viscous, and sour milk or cream, 
therefore, will churn more readily than sweet for 
this reason. The viscosity of the milk must be 
distinguished from the thickness of the milk, due 
to the coagulation of the casein. Souring of the 
milk renders it less viscous, but at the same time 
by coagulating the casein renders it thicker and 
less fluid. 

The temperature. — The temperature is the most im- 
portant condition affecting churning. Whether the 
particles of fat shall unite as they pass by one 
another when the liquid is in motion, depends very 
largely upon their temperature and degree of plas- 
ticity. If the temperature is too low, the globules 
of fat are so hard that when they hit one another 
they do not stick together. If, on the other hand, 
the temperature is too high, the effect of agita- 
ting the globules of fat is, instead of causing them 
to unite, to break them up into still smaller glob- 
ules, and so render the emulsion more permanent. 
The range of temperature through which the parti- 
cles of fat may be made to unite is considerable. 
The extreme limits may be placed at from 46° to 
80° F. But while butter may be churned from 



136 Mill' and Its Products. 

milk or cream through this wide range of tempera- 
ture, the quality of the butter is very seriously af- 
fected. The butter is in the best condition when it 
is churned at such a temperature that the particles 
of fat unite readih', and when united form firm 
masses or granules of butter. The temperature at 
which this desirable end is brought about varies 
under a wide range of conditions, the most impor- 
tant of which are the following: The individuality of 
the animal ; the period of lactation ; the nature of 
the food of the cows ; the season of the j-ear. 
These conditions are all conditions which affect the 
melting point of the butter fat. The higher the 
melting point of the fat, the higher the tempera- 
ture at which the milk should be churned, and the 
lower the melting point of the fat, the lower the 
churning temperature. Any condition which tends 
to make the butter fat hard will necessarily be fol- 
lowed by a rise in the churning temperature, and 
any condition which tends to make the butter fat 
soft will for the same reason be followed by a 
fall in the churning temperature. It is impossible, 
then, to name any single temperature which is the 
best or even the proper one at which to churn ; 
but while there is a considerable range of tempera- 
ture, which under different conditions may give the 
best results, still this range is not so wide as the 
range of temperature at which it is possible to 
churn, and the limits may perhaps be placed at from 
50° to 66° F. In general, the lowest temperature 
compatible with securing butter in a reasonable 



The Nature of tJie Afjitation. 137 

length of time will give butter of the best quality. 
The lower the temperature at which the butter is 
churned, other things being equal, the more com- 
pletel}' will the butter be removed from the butter- 
milk, the longer will be th^ time required for churn- 
ing, and the less casein will be found in the butter. 
The nature of the agitation. — It is generally be- 
lieved that the best results follow from agitating 
the cream in such a way that the particles of fat 
are subject to more or less concussion, though it 
is not at all necessary that this concussion should 
take place. Mere gentle stirring of the cream, if 
continued long enough, will bring butter, and agi- 
tating the cream by passing bubbles of air through 
it will also cause it to churn. Many churns have 
been devised which bring about the churning bj^ 
agitating the cream with floats or paddles, and in 
the old-fashioned dash churn there was a minimum 
amount of concussion, the motion being largely that 
of stirring. Where the agitation is brought about 
by the use of paddles or stirring instruments, the 
texture of the butter is usually injured, because of 
the effect of the stirring motion upon the grain of 
the first particles of butter formed. The best churns, 
then, are entirely hollow vessels, barrel or box, 
which bring about agitation of the cream through 
concussion of the particles upon the sides of the 
rotating churn. The churning depends, also, upon 
the rate of agitation; the faster the motion to 
■ which the particles of cream are subjected, the 
quicker will be the (diurning. In this respect the 



138 



Mill' and Its Products. 



motion of the particles and the motion of the churn 
must not be confounded. If the motion of the churn 
is increased so that sufficient centrifugal force is gen- 
erated to cause the particles of cream to partake of 




Fig. 16. Barrel power cluirii. 

the motion of the churn, then, though the particles 
may pass through space at a greater rate of speed, 
the motion of the particles upon each other will be 
lessened. A maximum motion of the particles upon 
each other is obtained when the speed of the churn 
stops just short of setting up centrifugal force in 



Size and Character of Fat Globules. 



139 



the churn. This will be found to correspond to a 
motion of the particles of cream of about 700 feet per 
minute. 

The quality of the glob ides of fat. — The quality of 
the globules of fat, both as to their size and char- 




Fig, n. Square l)OX power cluirii. 

acter, bears an important part in the phenomena 
of churning. So far as the hardness or softness of 
the fats are concerned, this has already been treated 
of under the effect of temperature; but temperature 
is not the only influence which causes variation in 



140 



Milk and Its Products ^ 




Fig. 18. "Fargo" combined cliiirii and 
butter worker. 



the hardness or softness of the fat. The relative 
proportions of hard and soft fats vary considerably. 

When the soft fats 
predominate, the 
chnrning is easier 
than when they are 
in less proportion . 
The size of the fat 
- globules also bears 
an important part in 
the ease and time 
required for churn- 
ing-. In passing through a mass of liquid two large 
globules are more likely to hit each other than are 
two small ones, the relative probability of their meet- 
ing and hitting l^eing in proportion to the square of 
their diameters. 

TJte end of churn'nKj. — When the particles of fat 
have united to such an extent that they begin to be 
visible in the cream, the butter is said to "break," 
and from this time on the process of churning is rap- 
idly finished. Two things are to be observed in bring- 
ing the operation of churning to a close. In the 
first place, the churning should be continued until 
the separation of fat is as complete as possible. 
In the second place, the larger the masses of but- 
ter in the churning the more difficult is the re- 
moval of the buttermilk. If the cream is thor- 
oughh' and uniformly ripened, the separation will be 
more uniform and the churning more complete 
than when creams of different degrees of ripeness 



Conditions of Difficult Churning. 141 

are chnrued together ; but under various conditions, 
and from time to time, the completeness of separation 
varies with the size of the granules of butter; that 
is to say, if the granules have reached a certain size, 
it does not always follow that the fat has been re- 
moved from the buttermilk to the same degree, so 
that the size of the granules of butter is not a certain 
indication of the completeness of churning. When the 
churning process is complete, the buttermilk takes on 
a thin, bluish, watery appearance, quite distinct from 
the thicker creamj^ ai)pearance of the unchurned cream, 
and the churning should be continued until this con- 
dition of the buttermilk is reached, even though the 
granules are increased in size beyond the point favor- 
able to their best separation from the buttermilk. 
The higher the temperature at which the cream is 
churned, the greater the percentage of fat left in 
the buttermilk and the more casein will be incorpo- 
rated with the butter. 

Difficult churning. — Conditions often arise under 
which it is very difficult or impossible to cause the 
butter to unite in granules and separate from the Init- 
termilk. One of the chief diflfieulties accompanies 
a small and hard condition of the butter granules 
with a high viscosity in the cream. These con- 
ditions usually occur in the late fall and early win- 
ter months, when the cows are far advanced in lac- 
tation, and when they are often fed on dry food 
of a character to make hard butter fat. An im- 
proper ripening of the cream often accompanies 
these conditions, so that complaints of difficulty in 



142 Milk and Its Products. 

churning are usually numerous at this period of 
the year. These complaints readily yield to the 
proper treatment, which is indicated under the con- 
ditions affecting churning, and so far as is known 
there never occurs a condition under which it is 
absolutely impossible to churn the butter from any 
given sample of cream. The course to be followed in 
cases of this nature is, first, to add to the food of 
the cows something of a succulent nature, that will 
cause the secretion of milk to be greater in amount 
and not so viscous. Second, to further lessen the 
viscosit}^ b}^ bringing about a vigorous lactic acid 
fermentation in the milk, and in extreme instances, 
perhaps, diluting the cream with warm water or 
weak brine. Care must be taken that this dilution 
does not go too far, or difficulty in churning from 
the thinness of the cream will result. The produc- 
tion of lactic acid in good amounts and within a 
reasonable time seems to be an important means of 
overcoming these cases of difficult churning. It is 
not unlikeh' that some of the lower fermentations, 
which take place at temperatures below which the 
lactic acid germs are active, may in themselves have 
a retarding effect upon the churning. These cases 
of difficult churning are frequently accompanied by 
the production of an acrid or bitter putrefactive 
fermentation product in the cream. 

If the attempt is made to churn at an extremely 
low temperature, the agitation of the cream serves 
to incorporate with it bubbles of air, and the 
cream froths or swells. When this takes place, 



Helping Buffer to Break. ^' 143 

little can be done except to allow the cream to 
stand for several hours and then warm it np 
gradually four or five degrees before again starting 
the churn. There is very much less danger of swel- 
ling in the revolving churns than in dash churns. 

Frequently also, in cases when the attempt is 
made to churn at the extreme lowest point possible, 
the formation of butter stops just short of the 
breaking point, and further agitation does not result 
in an increase of butter. This may be overcome by 
slightly raising the temperature, or by the addition 
of a little water at a temperature of 85° or 90° F.; 
or, what is better, it can usually be brought about 
by the addition of a little dry salt to the churn. 
The solution of salt in the water of the cream 
seems to affect the viscosity in &uch a way that 
the formation of butter granules is greatly facilitated. 

When ripened cream is churned, there is usually' 
an evolution of gas immediately after the agitation 
commences. This is gas which has been formed by 
some of the fermentations going on in the cream, and 
the gas is liberated within the first five or ten min- 
utes. The temperature also rises two or three degrees 
during the operation, from the effect of the friction 
of the particles upon one another. 



CHAPTER IX. 

FINISHIXa AXD MAEKETIXa BUTTER. 

When the churning process is complete, it still 
remains to separate the buttermilk from the granules 
of butter, and to bring the whole into a solid, uni- 
form mass, suitable for consumption and properly 
flavored with salt. These operations may be per- 
formed in a variety of ways. Formerly it was the 
custom to continue the churning until the butter 
was in a measurably solid mass, when it was re- 
moved from the churn and the l)uttermilk expelled 
by pressure, at the same time that the salt was 
incorporated with the butter. Now the buttermilk 
is uniformly removed from the butter by washing 
with water in the churn, and in many instances 
the salt is incorporated with it during the whole 
or part of this operation ; but the more common 
practice is to wash the butter in the churn and to 
work out the surplus moisture and incorporate the 
salt upon a separate instrument, called a butter 
worker. 

Washing the tutier. — The churning should be 
stopped as soon as the buttermilk is clear and wa- 
tery. If the churning has been done at the right 
temperature and the cream properly ripened, this con- 

(144) 



WasJiing Butter. 145 

ditiou will occur when the butter grauules are not 
larger than kernels of wheat. As soon as the churn 
is stopped, the addition of a little cold water to the 
contents of the churn will facilitate the rising of 
the smaller globules of butter through the l)utter- 
milk. The buttermilk should then be drawn off 
from the bottom of the churn, and the butter al- 
lowed to drain thoroughly. After the butter is thor- 
oughl}' drained, water at a temperature of 45° to 
55° F. should be added in amounts equal to two- 
thirds the amount of buttermilk withdrawn. The 
contents of the churn should then be gently agitated, 
so that the w^ater may come in contact with each par- 
ticle of butter, but not to such an extent that the 
particles will compact themselves into larger masses. 
In about ten or fifteen minutes, this water should be 
withdrawn and the l)utter allowed to drain as before, 
after wdiich the butter should be w^ashed the second 
time in the same manner. This second water should 
run away clear, or with a very slig-ht milkiness. 
If it is at all milky, the butter should be washed 
again, and the washing continued until the water does 
run away clear. It is desirable that as little wash- 
ing be done as possible, and if care is taken in 
stopping the churning at the right moment, and in 
draining and washing the butter, two waters will be 
sufficient. The addition of a small amount of salt 
to the first w^ashing water will facilitate the removal 
of the buttermilk, l)ut will not add any perceptible 
saltiness to the Imtter. The way in w^hich the wash- 
ing is done perceptibly affects the quality of the 



146 Milk and Its Products 

finished butter, particularly so far as regards its tex- 
ture and percentage of water. The smaller the 
granules of butter when the churn is stopped, and 
the colder the water used, the more water will re- 
main in the butter without appearing in the form 
of drops. If the churning has progressed until the 
butter has formed masses the size of a hickory nut 
or larger, particularly if the butter is soft, it will 
be impossible to completelj^ wash the buttermilk from 
the butter, and the buttermilk must necessarily be 
removed in working. Such butter will always re- 
tain in its flavor traces of the buttermilk so incor- 
porated with it. 

The texture of the butter is also affected by the 
temperature of the wash water. If the butter comes 
soft, the attempt is usually made to cool it down 
rapidly by the addition of large amounts of very cold 
water. The butter can be hardened up in this way, 
but it will show the effect of sudden changes of 
temperature afterward much more strongly than if it 
were cooled down more slowlj^ Butter fat does 
not conduct heat rapidly, and to become thoroughly 
warm or thoroughly cool requires some little time. 
If, then, butter has been churned too warm, and 
comes in a soft condition, the washing process should 
be much prolonged. Use the ordinary amount of 
water and at the ordinary temperature, but allow the 
butter to remain in it until it has had sufficient time 
to thoroughly adjust itself to the changed condition. 
It can then be taken out and worked without dan- 
ger of quickly becoming soft again. There is also 



Working Butter. 



147 



danger of removing some of the more delicate flavor- 
ing oils of the bntter hy the use of too large an 
amount of very cold water. These flavoring oils are 




Fig. 19. "Eureka" hand butter-worker. 

slightly soluble, and more soluble at a low tempera- 
ture, so that the drenching with large amounts of 
very cold water has a tendency toward the produc- 
tion of a flavorless or tallowj' butter. 

WorJiing. — Working butter is an integral part of 
the process of manufacture, only in so far as it re- 
lates to the incorporation of the salt and bringing 
the butter into the compact form necessarj' for con- 
sumption, so that all w^orking beyond that which 
is necessary to bring about these two things is super- 
K 



14'8 



Milk and Its Products 



fluous, and, because of the danger of injuring the 
grain of the butter, is objectionable. The grain 
of the butter is least affected by working when this 
is done by pressure and at a temperature of from 
45° to 55° F. The amount of water that remains 




Fig. 20. " Masou " table butter-worker. 



in the butter depends, as before stated, upon the 
temperature and fineness of the granules. The finer 
and colder the butter, the more water will it retain. 

Salti)i(j. — Salt is added to l)utter solely for the 
sake of the flavor which it imparts. While salt has 
undoubted antiseptic properties, these play very little 
part in the preservation of butter, and need not be 
taken into consideration. The amount of salt, then, 
that should be added to butter depends entirely 



Salting Butter. 



149 



upon the taste of the consumer for whom it is in- 
tended, and may vary from a mere trifle to as 
much as 2X onnces for each ponnd of butter. 
The great majority of consumers, however, prefer 
an amount rangiug between % of an ounce and 1 
ounce to the pound. 'The addition of a uniform 




Fig. 21. "Centrifugal" or vertical butter- worker. 



amount of salt from day to day is a matter of 
considerable importance in securing a uniform qual- 
ity of butter, and the amount of salt should, there- 
fore, be based upon the least variable factor possi- 
ble. It will be found that from day to day the 
size of the granules of butter when washed, and the 



150 Millc and Its Products. 

amount of water adhering to tliem, will vary consid- 
erably, so that the weight of washed and drained but- 
ter will not bear any definite relation to the amount 
of finished butter, and if the attempt is made to gauge 
the salt bj' the weight of di'ained butter, it will be 
found that the degree of saltness will vary considera- 
bly, because when more water is contained in the 
butter much more of the salt will pass out with 
the brine. When a separator is used in creaming, 
the weight of cream will be found to bear a closer 
proportion to the weight of finished butter than 
either the original weight of the whole milk or the 
weight of the washed and drained butter, and the 
more uniform salting will l^e ol^tained if the salt 
is added in the ratio of a certain percentage of 
the weight of the cream. The salt should be added 
so that it can be readily and uniformly incorporated 
with the whole amount of butter. This is con- 
veniently done while the water is being expressed 
from the butter in the worker, and the working 
should continue until the salt has completely dis- 
solved, because the salt has a deepening effect upon 
the color of the butter, and if some undissolved 
portions remain, these, afterwards dissolving in the 
water contained in the l^utter, will make a strong 
brine at that particular point, and consequently a 
deeper color, and mottled or streaked butter is the 
result. 

The salt should be dry, of uniform grain, and 
should readily and completely dissolve to a clear 
solution. Those brands of salt which are made from 



PacMng BtUter. 151 

the natural crystal give the best results so far as re- 
maining dry and freedom from caking are concerned. 

Brine salting. — With manj- who prefer a butter 
slightly salted, it is sometimes convenient to add 
the salt through the medium of brine, rather than 
to mix it with the butter in a diy condition. The 
advantages of brine salting are that a light amount 
of salt maj' be uniformh' incorporated with the 
butter. It is not possible to incorporate with the 
butter a large amount of salt in this way. Where 
well -drained butter is salted at the rate of one 
ounce to the pound, there will remain in the but- 
ter about 3 per cent of salt. Where butter is 
washed twice with a saturated brine, there will re- 
main in the butter when worked about 2 per cent 
of salt. In salting butter in this manner, it is nec- 
essary that the brine should be prepared before- 
hand. This is best done by dissolving the salt in 
warm water, as much as the water will hold, and 
then cooling it to the proper temperature to add to 
the butter. The brine in this instance may take the 
place of the second wash water. After the brine 
has remained upon the butter five or ten minutes, 
it should be withdrawn and additional salt added to 
it, or a second portion of saturated brine added and 
left upon the butter for a similar length of time, 
after which the brine may be withdrawn and the 
butter worked in the ordinarj' manner. 

Facl'ing and marlxPting. — After the butter has 
been worked until the salt is completely dissolved 
and a sufficient amount of w^ater removed, it is 



152 Milk and Its Products. 

ready for packing. Butter that is to be packed 
and held for any considerable length of time should 
be worked drier than when it is intended for im- 
mediate consumption. Fresh butter is most highly 
esteemed in most markets when it contains about all 
the water that it will hold, but if such butter is 
held for any length of time the evaporation of water 
from the surface will lead to a deposition of salt, 
which detracts much from its appearance and sala- 
bleness. An ideal package for butter is one that is 
light, strong and tight. None of the packages 
in ordinary use are perfect in all of these respects. 
Wooden packages, though light and strong, always 
leak more or less and let in air. Tin packages 
are more or less objectionable because of the action 
of the salt upon the tin, and iron, and glass, and 
crockery packages, although tight and clean, are 
heavy and subject to breakage. Packages made of 
paper or Avood pulp have been used to some extent, as 
have also packages of these materials covered with 
paraffine, but they do not make a very attractive 
package. All things considered, tight, smooth, well- 
made tubs of ash, spruce or oak make the most 
available package. All wooden packages possess the 
characteristic flavor of the wood, which may be im- 
parted to the butter to a greater or less extent if 
it is allowed to remain in them very long. In 
order to obviate this, the odor of the wood should be 
removed as much as possible before the butter is 
packed. The package should be thoroughly steamed, 
and then filled wdth hot water in which some salt 



Composition of Butter. 153 

has been dissolved, and allowed to stand at least 
twenty -fonr hours, after which it should be scalded 
a second time and then cooled with cold water. 
Butter may also be packed in prints or moulds, 
especially for immediate consumption. The demand 
for butter in this form is increasing, and for nearby 
markets it is one of the most desirable forms of 
packing. In cool weather and with proper precau- 
tions, prints may also be shipped considerable dis- 
tances with success. Prints are usually made in 
pound and half-pound sizes, intended to go directly 
upon the table in the shape in which they leave 
the manufacturer. Various shapes and sizes of prints 
have been made, but since the great increase in the 
demand for butter in this shape, a standard size for 
pound prints has been settled upon that makes a 
rectangular print, 4% x 2% x 2% inches. These 
prints are wrapped in parchment paper and packed 
in specially made carrying boxes. 

Composition and quality of hiitter. — The average 
composition of butter is about as follows: 

Fat 85 per cent. 

Casein 1 per cent. 

Salt 3 per cent. 

Water 11 per cent. 

The percentage of fat should not fall below 80 per 
cent nor the water rise above l^^-per^^^^enL.,^ The per- 
centage of casein should not exceed 4 per cent. The 
percentage of fat in butter of good quality often rises 
to 86 or 88 per cent. The quality of butter is 
judged upon its flavor, texture, color, amount of salt, 



154 Milk and Its Products. 

and its general style and appearance. Butter of good 
flavor should have the characteristic flavors well pro- 
nounced. It should be free from any rancidity, and 
clean and pure so far as any extraneous flavor is con- 
cerned. The determination of the flavor of any sam- 
ple of butter is entirelj' one of individual judgment. 
To some a high flavor is one in which the flavoring 
oils are developed almost to the verge of rancidity; 
in others, high flavor means a certain amount of the 
flavor of sour milk or buttermilk ; with still others, 
that butter is esteemed of the best flavor that is 
cleanest and purest. The true bouquet of high -class 
butter is a mild, distinct, volatile flavor or combina- 
tion of flavors extremely difiicult to describe, and only 
met with in perfection under the best conditions. 

The texture of butter depends upon the state of 
the granular condition of the fats. When the butter 
is first formed in the churn it makes its appearance 
in the shape of minute irregular granules. In the sub- 
sequent process of manufacture these granules never 
completely lose their individuality, and constitute the 
so-called grain of the butter. The more distinctly 
the individuality of the granules is marked in the 
mass of butter, the better the texture. The texture 
of the butter is shown by an appearance like broken 
cast iron when a mass of butter is brokeu in two 
transverselj', and when a metal is passed through the 
butter, as a knife or trier, if the butter be of the 
best texture, no particles of fat adhere to it. The 
texture of the butter is deteriorated if the particles 
of butter are churned in too large masses, and if 



Judging Butter. 155 

in the process of working the individual particles 
are made to move upon one another at too high a 
temperature. The mere warming of the butter to a 
point approaching the melting point destroys the 
grain upon subsequent cooling, even though the mass 
of butter may have been undisturbed. 

The color of the butter should be a clear, bright, 
golden yellow, such as is naturally jdelded by the 
cow when feeding upon fresh pasture grasses. The 
natural color of the butter is affected very largely by 
the race of the cow, by the character of the food, 
and by the period of lactation. Scarcely any breed 
of cows will yield a butter of ideal color upon dry 
food late in their period of lactation. On the other 
hand, one or two races upon fresh pasture will 
yield a butter of too high a color to suit the most 
critical trade. The great mass of butter made is 
artificially colored. For this purpose a large va- 
riet}^ of substances has been used, but practically 
the only coloring matter now emplojed is a prepara- 
tion of annatto (a coloring matter in the seed pulp 
of Bixa orellava) in some neutral oil. This coloring 
matter is prepared of such strength that onlj' mi- 
nute quantities are necessary to be added to the 
cream to produce butter of the proj^er shade. Butter 
artificially colored should be uniform, of a bright 
golden yellow color, free from mix reddish tinge. 
The demand of different markets varies considerably 
in regard to the shade of color desired. 

In regard to salt, the quality of the butter is 
not necessarily affected bj* the amount of salt, that 



156 Milh and Its Products. 

being established by the demand of the trade for 
which it is intended, but the salt, in whatever de- 
gree added, should be completely dissolved, and 
should be uniform throughout the whole mass of 
butter. The finish of the butter, in whatever form 
packed, should be such that it will present a neat, 
clean, attractive appearance. The different qualities 
of butter are ranked in importance in accordance 
with the following scales : 

Flavor 40 to 45. 

Texture 25 to 30. 

Color 10 to 15. 

Salt 10 

Finish 5 



CHAPTER X. 

MILK FOR CHEESE MAKING. 

Cheese is a product manufactured from milk, into 
which a large part of the solids are gathered together 
in such form that their nourishing qualities are re- 
tained, at the same time that they are brought into 
a condition capable of preservation and convenient 
for transportation. ,The solids which are concerned 
in the manufacture of cheese are the casein, the fats, 
and a considerable portion of the ash. The albumin, 
nearly all of the sugar, about one -third of the ash, 
and a small part of the fat, escape during the course 
of manufacture. The elimination of a large part of 
the water is the chief step in the process of cheese 
making. In general terms, cheese consists of about 
equal proportions of water, fat and casein, with a 
certain amount of salt and minute quantities of milk 
sugar and ash. In milk, the casein exists in a state 
of minute suspension or semi-solution. The essential 
step in securing the separation of the water is in 
rendering the casein insoluble. Casein, like most 
albuminous organic substances, exists in two forms, 
known respectively as the soluble and the insoluble 
or coagulated form, and the change from solution to 
insolubility is termed coagulation. In the case of 

(157) 



158 Milk and Its Products. 

casein, coagulation may be brought about by several 
reagents, but the one universally employed in cheese 
making is a soluble ferment found in the stomachs 
of young mammalia and in certain other animals, 
known as rennet. By the addition of rennet to 
milk, the casein takes on the form of a homogene- 
ous gelatinous solid, and in changing its form en- 
closes in its mass the globules of fat. In bringing 
about the change in the casein in this way, the ren- 
net acts by contact ; that is, its own constitution is 
in no waj' disturbed, and a minute amount of rennet 
is capable of causing the coagulation of a large 
amount of milk. 

Quality of milTx for cheese maMng. — While it is 
scarcely necessary to demonstrate that milk is val- 
uable for butter making in proportion to the amount 
of fat it contains, the proposition that its percent- 
age of fat is also a measure of the value of nearly 
all milk for cheese making has not been so readilj- 
accepted. Indeed, until within a very short time, the 
prevailing opinion among dairymen and cheese -makers 
has been that a milk poor in fat was likely to be 
rich in casein, and hence more valuable for cheese 
making purposes. But both fat and casein are con- 
stituents of cheese, and both are of nearly equal im- 
portance ; hence, the richer a milk is in fat, the 
more cheese it will make, and recent research has 
shown that for milks containing a normal amount of 
fat the yield of cheese will be nearly proportional to 
the percentage of fat in the milk. 



Relation of Fat to Casein 



159 



Van Slyke,''^ in a series of investigations extend- 
ing over several years, and inclnding the milk of not 
less than fifteen hundred different cows, found that as 
the percentage of fat increased the percentage of 
casein increased in a nearly constant ratio ; or, to 
quote his own words : "While we have noticed con- 
siderable variation when we considered individual 
herds, w^e have found that, as a rule, there were two- 
thirds of one pound of casein for each pound of 
fat in the milk, whether the milk contained 3 or 4 
per cent of fat ; though this normal relation was con- 
siderably affected in the season of 1893 by the effects 
of drought upon the pastures. ^ '^ ''"^ * When 
the amount o| fat in the milk increased beyond 4% 
per cent, there w^as a gradual but slight diminution 
of casein for each pound of fat." 

The accompanj'ing tables give the data upon which 
Dr. Van Slyke's opinions were based : 



Table showing relation of fat to casein in normal milk. 













Average 


Group. 


Per cent of 
fat in milk. 


Number of 
samples. 


Average per 

cent of fat in 

each group. 


Average per 
cent of casein 
in each group 


pounds of 

casein for 

each pound of 

fat. 


I. 


3 to 3.5 


22 


3.35 


2.20 


0.66 


II. 


3.5 to 4 


112 


3.72 


2.46 


0.66 


III. 


4 to 4.5 


78 


4.15 


2.70 


0.65 


IV. 


4.5 to 5 


16 


4.74 


3.05 


0.64 


Y. 


5 to 5.25 


7 


5.13 


3.12 


0.61 



*New York Agricultural Experiment Station, Bulletin, No. 68, New Series. 



160 Milk and Its Products. 

Table showing relation of fat in milk to yield of cheese. 



Group. 


Per cent of fat in 
milk. 


Pounds of green 

cheese made from 100 

lbs. of milk. 


Pounds of green 
cheese made for one 
pound of fat in milk. 


I. 

II. 
III. 
IV. 

V. 


3 to 3.5 
3.5 to 4 

4 to 4.5 
4.5 to 5 

5 to 5.25 


9.14 
10.04 
11.34 
12.85 
13.62 


2.73 
2.70 
2.73 
2.71 
2.66 



Babcoek* tabulated the results of a large num- 
ber of observations in factories in Wisconsin in the 
accompanying tables, and while agreeing in the main 
with Van Slyke, was forced to conclude that, " at the 
same season of the year, rich milks do not yield as 
much cheese in proportion to the fat i\\e\ contain as 
do poor milks, but that a rich milk toward the end of 
the season may do as well as a much poorer milk 
earlier in the season." 

Table showing yield of cheese in Wisconsin factories according to 
2^er cent of fat in vdlk. 



No. of 
groups. 


No. of 
reports. 


Range of fat 
per cent. 


Average per 
cent of fat. 


• Average 
yield of 
cheese per 
100 lbs. milk. 


Lbs. of cured 

cheese for 

1 lb. fat. 


1 


24 


under 3.25 


3.126 


9.194 


2.941 


2 


90 


3.2.5—3.50 


3.382 


9.285 


2.730 


3 


134 


3.50—3.75 


3.C00 


9.407 


2.613 


4 


43 


3.75—4.00 


3.839 


9.806 


2.562 


5 


4G 


4.00—4.25 


4.090 


10.300 


2.512 


6 


20 


over 4.25 


4.447 


10.707 


2.407 


All groups. . 


347 




3.64 


9.566 


2.628 



*Wisconsin Agricultural Experiment Station, 11th Annual Report, p. 137. 



Relation of Fat to Casein. 161 

Table shoicing yield of cheese in Wisconsin factories hy months. 



Mouth. 



No. of 
reports. 



April 

May 

Juue 

July 

August . . . 
September . . . 
October . . . . 
November . . 

Whole seasou 



22 
68 
66 
63 
49 
36 
28 
15 



347 



Average per 
cent of fat. 



3.480 
3.493 
3.497 
3.554 



Average 

yield of 

cheese per 

100 lbs. milk. 



9.154 
9.447 
9.367 
9.231 



Lbs. of cured 
cheese for 
1 lb. of fat. 



3.634 


9.335 


3.836 


9.995 


4.076 


10. .362 


4.254 


10.947 


3.64 


9.566 



2.630 
2.704 
2.679 
2.593 
2.568 
2.594 
2.591 
2..573 



2.628 



TahJe shoicing yield of cheese for one pound of fat for each month. 



Perceut of fat. ^^S'.,;!'"'^ Juue 



Under 3.2;! 

3.2.5—3.50 

3.50—3.75 

3.75—4.00 

4.00—4.25 

Over 4.25 



I I October 

July. August. Sept. | and 

Novemb'r 



No. j No. 

I 

12—2.96 6—2.99 

33-2.73 23—2.74 

34-2.62 32—2.63 

7— 2. .53 3—2.47 



3—2.56 
1—2.15 



.30 



No. No. 

3—2.89 I 3—2.88 

20—2.70 11—2.73 

29—2.58-' 24— 2..54 

7— 2.4(i 7—2.5:; 

4-2.33 3-2.35 



3—2.85 
10—2.67 
13-2.61 

9—2.47 



1—1.95 1—2.13 



5—2.81 

6— 2. 62 

1.5—2.64 

17—2.46 



On the other hand, Dean* has found that uni- 



* Ontario Agricultural College, 21st Annual Report, p. 44. 



162 



Millc and Its Products. 



forml}^ a rich milk yields less cheese in proportion 
to the fat contained in it than a poor milk. His 
experiments covered a whole season's work in a 
single factory, the average resnlts of which are shown 
in the following table: 

Yield of cheese from rich and poor milk. 



April . . . 
May .... 
June . . . . 
July .... 
Aii^ust . . . 
September . 
October . . 
Average 



Per cent of fat in jPounds of green cheese 
Xum- milk. ^^^' ^^"^ pound of fat 

ber of i 
experi- 



ments. 



1.3 
15 



12 

12 



14 
14 



13 
1.3 



12 
12 



13 
13 



in milk. 



Richer 
milk. 



4.21 

4.09 
3.94 
3.78 
3.82 
4.01 
3.99 



3.98 



Poorer 
milk. 



3.39 
3.30 
3.16 
3.00 
2.91 
3.06 
3.26 



Richer 
milk. 



2.66 
2.68 
2.68 
2.73 
2.74 
2.68 
2.82 



3.15 



2.71 



Poorer 
milk. 



2.86 
2 84 
2.94 
3.06 
3.14 
3.06 
3.05 



2.99 



The practical bearing of the relation of the fat 
to the casein arises in the qnestion as to whether, 
where milk is bonght for cheese making, it shonld 
be paid for by weight or according to its percent- 
age of fat. It does not require proof, that to pay 
an equal price per pound or hundred weight for 
milk of all qualities is a gross injustice to those 



Relation of Fat to Casein. 163 

who produce the richer milks. If there were a 
quick, accurate method of determining casein, the 
logical practice would be to pay for the milk upon 
the basis of its known content of both fat and 
casein; but failing in that, it is well to examine 
in how far we may fall back upon the percentage 
of fat, the determination of which is both quick 
and accurate, as a measure for determining the 
value of milk for cheese making. While there is 
some disagreement, it seems to be pretty well settled 
that a milk rich in fat is also richer in casein, 
and with milk of ordinary quality, including prob- 
ably nine -tenths of all the milk produced, nearly in 
proportion to the percentage of fat. So that, even 
if the richer milk does yield a little less cheese 
for each pound of fat, the percentage of fat is a 
much more nearly just measure of its cheese -pro- 
ducing power than is the w^eight of the milk, the 
measure now commonly employed. Further, when 
the milk is so rich in fat that the casein falls 
considerably below its normal ratio to the fat, the 
resulting cheese will be so much richer in fat 
that it will be of considerably- better quality, and 
such milk, when pooled with milk poor in fat, will 
so bring up the quality of the whole product, that it 
should be paid for at a correspondingly higher rate. 
The conclusion, therefore, is that the percentage of 
fat is by far the most accurate measure at present 
available for the determination of the cheese -produ- 
cing value of milk, and that milk is practically valu- 
able for cheese making in proportion to the amount 



164 



Milk and Its Products. 



of fat that it contains, and should be paid for ac- 
cordingly. 

Loss of fat in cheese making. — It has been a gen- 
erally accepted idea by cheese -makers, that the neces- 
sary loss of fat in the whey is much greater 
when the milk contains a high percentage of fat. 
Indeed, the statement has been frequently made 
that all the fat in the milk above 4 per cent is 
lost in the whey. This idea has had much to do 
with the disinclination to value milk for cheese 
making according to its percentage of fat, and, in 
fact, has been a chief argument in favor of the 
manufacture of skimmed or partly skimmed cheese. 

The following table b}' Van Slyke"^'^ shows that 
this idea is erroneous, and that the loss of fat in 
the whey need be proportionatelj^ no greater when 
the milk is rich than when it is poor in fat. 

Table slwwing amount of fat lost and recovered in making cheese. 



Number of 
experi- 
ment. 


Pounds 

of fat 

in 100 

lbs. 

of milk. 


Pounds of 
fat lost in 

100 lbs. 

of milk. 


Pounds of fat 

recovered in 

100 lbs. of 

milk. 

2.196 
2.817 
3.603 
3.677 
4.341 
4.399 
4.427 
5.775 
3.431 


Pounds of fat 

lost in whey 

from 100 lbs. 

of fat in 

milk. 


Pounds of fat 
recovered in 
green cheese 
from 100 lbs. 

of fat in milk. 


1 

2 

3 

4 . . • . . 


2.35 
3.01 
3.88 
3 96 


0.154 
0.193 
0.277 
0.283 
0.359 
0.331 
0.373 
0.715 
0.269 


6.55 
6.42 
7.15 
7.14 
7.64 
6.99 
7.77 
11.01 
7.26 


93.45 
93.58 
92.85 
92 86 


5 • .... 

6 

7 

8 

9 


4.70 
4.73 
4.80 
6.49 
3.70 


92.36 
93.01 
92.23 
88.99 
92.74 



Other investigators have abundantly confirmed 
these results. 



*New York Agricultural Experiment Station, Bulletin No. 37, p. 681. 



Cooling and Aeration. 165 

Cooling. — All that was said in Chapter V. on 
''market milk,'' in regard to cleanliness in drawing 
the milk, applies equally well to milk that is in- 
tended for cheese making, but where milk is made 
into cheese it is not necessary, nor, indeed, is 
it desirable, that the lactic acid fermentations be 
checked further than is necessary to allow the milk 
to come into the cheese maker's hands in the best 
condition. In cheese making, the fermentations of 
the milk play a most important part, and while it 
is not at present known just what fermentations are 
necessary or most desirable, sufficient is known to as- 
sure us that a certain amount of lactic acid is not 
only desirable but necessary for the cheese making 
process, and enough further is known that those fer- 
mentations which attack the protein substances, and 
result in the formation of strong flavors, taints and 
gases, are all undesirable in cheese making. For 
the purpose of cheese making, it is desirable that the 
fat should separate from the other constituents of 
the milk as little as possible, and to that end the 
previous treatment of the milk should be such that 
the separation of cream will be held back as much 
as possible. One of the best means of doing this 
is to cool the milk to the temperature of the air 
while it is kept constantly in motion. This, be- 
side helping to keep the cream mixed with the milk, 
will also favor the escape of any volatile animal 
products that may be present in the milk, known 
under the collective name of animal odor, and 
which would otherwise impart objectionable flavors 
to the cheese. 



166 



Milh and Its Products. 



Aeration. — Passing the milk through an elevated 
strainer in such a manner that it may fall in 
finely divided drops or streams through the air be- 
fore it reaches the can, is one of the best means 
of bringing about this end. This is known as 
aeration. It cannot be depended 
upon to destro}^ or even check the 
germs of fermentations which may be 
present in the milk, beyond that 
due to the reduction of temperature. 
It is not desirable that milk in- 
tended for cheese making should 
be cooled much below the tempera- 
ture of the air, and one of the best 
preparations of milk intended for 
cheese making is to allow it to 
remain where it will be freely ex- 
posed to a pure and moderately cool 
atmosphere. Under ordinary condi- 
tions, the milk of the evening and 
the sncceeding morning are manufactured together, 
and the treatment indicated is naturally that of the 
night's milk. It is highly desirable, however, that 
the milk of the morning should be cooled to the 
temperature of the atmosphere before it is taken to 
the factory, and under ordinarj^ conditions the milk 
of the night and morning should be taken to the 
factory in separate cans. 

Bipening. — The lactic acid fermentation is prob- 
ably one of the most important factors in all the 
steps of cheese making, and to know to what ex- 




Fig. 22. "Hodgkiu" 
elevated strainer. 



Rennet Tests. 



167 



tent it has progressed before the process begins, is 
exceeding!}' important to the cheese maker. To this 
end, several convenient tests may be applied. The 
veteran, who has attained skill through long manip- 
ulation, can tell with a fair degree of accuracy 
through the sense of smell and taste the amount 
of lactic acid present in his milk, but this is not 
a safe enough guide for those who are inexpe- 
rienced, or those who expect to make a uniform 
product in a uniform 
way from day to day. 

Rennet tests. — The 
percentage of lactic 
acid present in the 
milk can readily be 
determined directly by 
titration with a stand- 
ard alkali, but the 
amount of lactic acid 
present is also quite 
readil}' dete r m i n e d 
by the len g t h of 
time required for ren- 
net coagulation, since 
ren net acts more 
quickly upon milk 
the riper it is, and 
upon this fact two 
or three simple tests 
have been devised. 
The simplest of these test is made. 




Fig. 23. 
b, 50 c. 



Monrad rennet test, a, 5 c. c. pipette; 
c. graduated flask; c, cup in which 



168 



Milk and Its Products. 



is to add a spoonful of rennet of known strength 
to a teacnpful of milk and, after stirring the two 
together thoroughly, to note carefully the time re- 
quired for coagulation. Another and more exact 
method, known as the Monrad test, is made as fol- 
lows: To a measured quantity of milk at a given 
temperature a measured quantity of rennet of known 
strength is added; ordinarily the commercial rennet is 
diluted nine -tenths for this purpose. The rennet is 
thoroughly stirred with the milk, and the time re- 
quired for coagulation is carefully noted. This is 
simply a development of the cup test, and is better 
because of its greater delicacy and accuracy; the 
milk and rennet being more carefully measured, and, 
diluted rennet being used, a wider range of delicacy 

is reached. Still 
another form of ren- 
net test, known as 
the Marschall test, 
has been devised. 
In this test the milk 
is measured into a 
vessel, one of whose 
Ludes is graduated 
and in the bottom 
of which there is a 
minute orifice. The 
T.. .,. ,, , ,, ... rennet is added to 

Fig. 24. Marschall rennet test. 

the milk, and the 
vessel so placed that the milk can escape from the 
hole in the bottom. So long as the milk remains 




Ripening the Milk. 169 

fluid the stream is continuous, but as soon as the ren- 
net takes effect and a clot is formed, the stream stops, 
and no more escapes. The number of spaces of milk 
which escape is taken as the measure of the ripeness 
of the milk. When the percentage of lactic acid is 
great the stream stops sooner than where little acid 
has been formed, so that in the ripe milk a less 
number of spaces shows upon the side of the vessel 
than in the unripe milk. 

Degree of ripeness necessary. — By ripeness of milk 
for cheese making is meant, as in the case of but- 
ter making, the degree of lactic acid development that 
has taken place. For cheese making, the develop- 
ment of lactic acid should not have proceeded so 
far that the milk is distinctly sour to the taste, and 
it should have proceeded far enough so that the 
whole process of cheddar cheese making, from the 
time of adding the rennet to putting the cheese in 
press, will take not more than six hours. This will 
be indicated bj' a rennet test of 2% spaces on the 
Marschall apparatus, or a rennet test of one minute 
on the Monrad test, when 5 c. c. of diluted com- 
mercial rennet extract (1 part rennet to 9 of water) 
are added to 200 c. c. of milk. 

Starters. — In very many cases the milk, when 
brought to the factory, will not be sufficiently ripe 
to give the tests indicated above. In that case it 
should be allowed to ripen before the cheese making 
process begins. This may be brought about by 
heating the milk up to 85° F., when the germs 
already present become more active; but the time 



170 Milk and Its Products. 

required for the ripening will be shortened, and more 
uniform results be obtained if, in addition to the 
warming, an artificial starter is used. This may be 
any material containing the germs of lactic fermen- 
tation in active condition. The whey saved from 
the previous day, or milk naturally or artificially 
soured, may be used. An extremely convenient 
form of starter is made by preparing an artificial 
ferment in the following way: Ten pounds of 
whole milk are sterilized at 180° F., then cooled to 
90°, and sufficient commercial dry lactic ferment 
added to secure coagulation in twenty -four hours. 
When coagulated this is added to the extent of 10 
per cent to enough w^hole milk to make sufficient 
starter for one day's use. The amount of starter 
to be added for the purpose of ripening the milk 
should be from 2 to 5 per cent, varying with the 
temperature of the air and the amount of ripeness 
that it is necessary to develop after the milk reaches 
the factory. Enough of the ferment should be re- 
served each day to prepare ferment for the following 
day from whole milk; and with care that the ves- 
sels in which the ferment is made are kept clean 
and sweet, a single ferment may be propagated for 
from ten days to two weeks. Such a ferment will 
give more uniform results, and is less liable to in- 
troduce taints and bad flavors, than a ferment made 
from sour whey, and with a little care and atten- 
tion, the fermentation will go on regularly from day 
to day. 

Eennet, — The ordinary source of rennet is the 



Preparation of Rennet. 171 

fourth or digestive stomach of a calf that has not 
yet ceased to live upon milk, though rennet is also 
found in the stomachs of puppies and pigs, and the 
latter have come to be of almost equal importance 
with calves as a source of rennet. The active prin- 
ciple of the rennet is found in the folds of the 
lining membrane of the stomach of the animal, and 
is greatest in amount when a full meal is just di- 
gested. The rennet should be obtained from an ani- 
mal of some age. Still-born calves, or calves less 
than three daj's old, furnish a rennet of very in- 
ferior quality. The calf should be slaughtered three 
or four hours after it has had a full meal, and the 
fourth stomach carefulh^ taken out. This should be 
emptied by turning inside out and any particles 
of foi'eign matter carefully picked off ; it should 
not be washed with water. It should then be 
sprinkled with salt and stretched in such a manner 
that it will readily dry. 

At the present time the preparation of the rennet 
extract from the skins is entirelj^ a commercial one, 
and rennet so much superior, on account of its 
uniform strength and freedom from taints, is fur- 
nished in this way that it is not advisable to prepare 
the rennet for use from the skins. In the prepara- 
tion of the extract, the skins are soaked in warm 
water to which a little salt has been added until the 
active principle has been completely removed from 
them. The resulting extract is filtered, and preserv- 
atives, in the shape of salt and a little saltpetre, 
are added. Eennet so prepared will x'etain its 



172 Milk and Its Products. 

strength and purity for a considerable length of 
time, if kept in a cool, dark place. 

Removal of whey. — After the coagulation of the 
milk is complete its constitution is as follows : 92.5 
parts soluble, 7.5 parts insoluble. The soluble por- 
tions are made up of water 87, sugar 4.5, albumin 
.75, ash .25. The insoluble are made up of casein 
3.25, fat 3.75, ash .5. The separation of these two 
is the chief task of the cheese maker, and is brought 
about partly by mechanical and partly by chemical or 
physical agents. The chief mechanical agents in 
the separation are cutting the curd, stirring, and the 
application of pressure. The chemical and phys- 
ical agents in effecting the separation are: First, 
application of heat ; second, development of lactic 
acid; third, addition of salt ; fourth, curing fermenta- 
tion. These various agents may be applied in va- 
rious degrees and in various ways, all of which have 
a greater or less effect upon the character of the 
resulting cheese, producing an almost endless variety 
of product. The process that we shall describe is 
one in common use in America, although first prac- 
ticed in England. It is known as the American 
Cheddar process, and is a modification in minor de- 
tails of the process employed in the Cheddar district 
in Somerset, England, as much as 250 years ago. 



CHAPTER XI. 

CHEDDAR CHEESE MAKING. 

The successive steps in the manufacture of Ched- 
dar cheese may be convenient!}' grouped into seven 
stages or periods, as follows : Period first, setting ; 
period second, cutting ; period third, heating ; period 
fourth, cheddaring ; period fifth, grinding ; period 
sixth, salting and pressing ; period seventh, curing. 

Period I., setting . — The rennet is most active at 
temperatures from near that of the body, 98° to 
100° F., up to about 130° F., and if added to the 
milk at these temperatures will most quickly cause 
coagulation, but at high temperatures there is more 
tendency of the fat to separate, and for this reason 
the milk is warmed to a degree sufficient to cause 
fairly rapid coagulation, and at the same time, not 
injure the fat. This will vary from 82° to 86° F., 
according to conditions. The milk, when brought to 
the factory, is collected in the vats and the whole 
mass gradually warmed up to the proper tempera- 
ture, with frequent gentle stirring to prevent any 
separation of the fat in the form of cream. When 
the whole mass is warmed up to 82° the milk is 
tested for ripeness, and if sufficiently ripe the ren- 
net Is added at once, but if the milk is insuffi- 

(173) 



174 Milk and Its Products. 

ciently ripe a starter is then added, and the milk 
allowed to stand at this temperature until a suffi- 
cient amount of acid has developed, care being 
taken that it is frequently stirred and no cream 
allowed to rise. 

The rennet should be added in sufficient quan- 
tity to cause the milk to coagulate in from ten to 
fifteen minutes, and to be ready for the knife in 
from thirty to thirtj'-five minutes. It was formerly 
supposed that the amount of rennet added had an 
effect upon the whole process of manufacture, and 
particularly upon the curing fermentation, but while 
the matter is still unsettled, later researches go to 
show that the influence of the rennet upon the 
curing is probably very slight. The amount of ren- 
net to be used will also vary with the strength of the 
extract ; two to three fluid ounces of rennet, of or- 
dinary strength, per thousand pounds of milk is 
sufficient. The rennet should be added to the milk 
in such a way that the coagulation will be uniform 
throughout the whole mass. If the rennet is added 
in full strength and at a high temperature, the 
milk will be immediately curdled as soon as the 
particles of rennet come in contact with it, and 
coagulation will begin in part of the mass before 
the rennet can be thoroughly united with the whole 
body of milk. The rennet should be diluted with 
twenty to fifty times its own bulk of cold water. 
The dilution renders the uniform mingling of the 
rennet with the milk easier, and the cold water 
keeps it inactive until it has been warmed up to the 



Setting and Gutting. 175 

temperature of the milk. So soon as the rennet is 
added, the milk should be quickly and carefully 
stirred, so that the rennet may be uniformly mingled 
with every part of it. This stirring should continue 
until the mixture of rennet and milk is complete, 
but should stop before any appearance of coagula- 
tion. The milk in the vat is then allowed to be- 
come quiet, and remains undisturbed while the pro- 
cess of coagulation is going on, the object being to 
secure a uniformly solid clot or coagulum through 
the mass. The action of the rennet is not instanta- 
neous ; the first appearance of coagulation is noticed 
by a slight thickening of the milk. This gradually 
increases until the whole mass is solid, and if left 
undisturbed the action of the rennet continues to 
contract the coagulated casein and cause a partial 
separation of the whey. As soon as the coagulation 
is strong enough, so that the casein will maintain 
its shape when broken, the contents of the vat are 
ready for the next step in the process. 

Period II., cutting. — The curd, as the coagulated 
casein is called, is ready for cutting when under 
strain it will break with a clean fracture. This is 
conveniently tested by gently inserting the finger in 
the curd in an oblique position and slightly raising 
it, when if the curd breaks clean across the finger 
it is sufficiently firm for cutting. Cutting is per- 
formed in order to facilitate the further contraction 
of the casein and the expulsion of the whey. For- 
merly the solid mass of curd was broken up into 
small pieces by any sort of an instrument that 



176 Milk and Its Products. 

might be at hand, or shnply with the hugers, no 
care being taken that the pieces of curd should be 
of uniform shape or size, but now gangs of steel 
knives, in one of which the blades are arranged 
horizontally and the other perpendicularly, are used 
to cut the mass of curd into cubes of about % of 
an inch in diameter. The fat is retained in the 
cheese by being enclosed in the meshes of the casein, 
and in breaking up the mass of casein, a certain 
number of fat globules is always set free. The 
care with which the cutting and subsequent hand- 
ling of the curd is done controls the loss of fat 
through this source. Formerly, the mass of curd 
was allowed to become very firm before cutting, but 
the more recent practice has shown that the best 
results in expelling the whey from the curd are 
reached when the curd is cut, so soon as it has 
sufficiently coagulated to maintain its form. The 
curd is cut by passing the horizontal knife through 
the vat, usually in a longitudinal direction, and then 
by passing the perpendicular knife both longitudi- 
nally and crosswise of the vat. It is immaterial 
whether the horizontal or perpendicular knives are 
used first. Some skilled cheese - makers prefer the 
one practice and some the other. The object to be 
attained is to break up the curd into as uniform 
a mass of kernels as possible, or, in the language 
of the cheese-maker, to secure an "even cut." After 
the curd is cut, the whey begins to escape, and the 
curd sinks to the bottom of the vat. If allowed to 
remain undisturbed, the cut surfaces of the particles 



Heating or Cooling. 177 

of curd readily unite, and in breaking them apart 
again more fat is lost. Hence as soon as the curd 
is cut, gentle agitation of the whole mass should 
begin. This agitation should be sufficient to cause 
the particles to move upon one another, but not 
violent enough to break them up. The curd rapidlj- 
shrinks and hardens ; more rapidly upon the outside 
than the inside. This soon results in the formation 
of a so-called "membrane," which not only tends 
to prevent the particles from sticking together, but 
affords some resistance to further breaking up. This 
"membrane" is pervious to water, but retains the 
globules of fat ; so as soon as the contraction has 
reached this point, or when the curd is well "healed 
over," the further expulsion of the water should be 
aided by heat, and this point begins the third step. 
Period III., heating or cooking. — The term "cook- 
ing," as applied to the manufacture of cheese, is a 
misnomer so far as it relates to any change in the 
composition or condition of the material through 
the effect of heat. By cooking any ordinary sub- 
stance is meant the application of a degree of heat 
sufficient to cause a coagulation of albuminous sub- 
stances or a breaking down of starchy ones. The 
degree of heat used in cheese making during this 
stage never reaches anywhere near this point, and 
never, except in rare instances, is a temperature of 
blood heat exceeded. The change to be brought about 
in this process is wholly the contraction of the curd 
and the consequent expulsion of water from within 
the particles. To this end the heat serves a two- 



178 Milk and Its Products. 

fold and important part. The curd is contracted to 
some extent by the action of the rennet still con- 
tinuing ; also to some extent by the direct applica- 
tion of the heat, but to a greater extent by the 
effect of lactic acid upon the curd, the production 
of lactic acid being greatly favored by the increased 
temperature. It is desirable that this contraction of 
the curd in the cooking stage go on uniformlj^ through- 
out the whole mass. The heat is therefore applied 
gradually and with constant stirring. As the parti- 
cles of curd shrink in size, the tendencj' for them 
to unite in masses constantly diminishes, and thej^ 
are broken with greater difficulty, so that while at 
first extreme care is necessary to prevent the par- 
ticles of curd from becoming broken, as the temper- 
ature rises, the stirring may become more rapid and 
vigorous. The heat should be raised slowly from 
the setting point of the milk up to 98° F., and it 
should not be more rapid than 2° in five minutes; 
and unless the lactic acid develops very rapidly it 
is better to take even more time than this. When 
the temperature of 98° F. is reached, the stirring 
may cease and the particles of curd be allowed to 
settle upon the bottom of the vat until the curd is 
thoroughly shrunken and a sufficient amount of 
lactic acid has been developed. At the end of the 
cooking stage the particles of curd should have 
shrunken to less than one -half of their former size, 
and should have become so hard that when pressed 
together between the hands, and the pressure sud- 
denly relaxed, they will fall apart, and show no 



Cheddaring or Matting. 179 

tendency to stick together. By this time there should 
have developed a sufficient amount of lactic acid so 
that the curd will draw out in fine threads a 
quarter of an inch long when applied to the hot 
iron. 

When the curd has reached the highest temper- 
ature, it may be allowed to settle, and a part of the 
whey may be drawn off the top of the vat. This 
is of advantage particularly when the development 
of lactic acid is likely to be rapid, and it is de- 
sirable to separate the whey from the curd in a very 
short time, but sufficient whey should be left to 
cover all of the curd two or three inches deep 
until sufficient acid has been developed for the 
cheddaring process. 

Period IV., cheddaring , or matting. — When suffi- 
cient acid has developed in the whey, it is di-awn 
off from the vat through the gate or by means 
of a syphon. The curd is then allowed to mat 
together into a mass, which is the distinctive fea- 
ture of the Cheddar process. This matting together 
may be done either in the vat or in a special 
vessel, called a curd sink. In the former case, 
when all the whey is run off the particles of curd 
are brought together upon the two sides of the vat 
and a channel opened between them, so that any 
whey held by the particles of curd may be al- 
lowed to escape. When the particles of curd are 
sufficiently matted together to maintain themselves in- 
tact, the mass is cut up into blocks about 8x8x12 
inches, and these blocks are turned over so that 

M 



180 Milk and Its Products. 

the part that was uppermost comes in contact with 
the bottom of the vat. A further draining of the 
whey takes place, and the blocks of curd are next 
piled upon one another two deep, care being taken 
in forming these piles that the parts that were ex- 
posed to the air are turned in. Later on the curd 
is piled again in still deeper piles, and as the pro- 
cess continues the mass is piled over and over 
again, care being taken that the exposed parts of one 
pile are put into the interior of the succeeding, so 
that the heat may be uniform throughout the whole 
mass. In the curd sink the manipulation is not 
essentially different. The curd sink is a square 
wooden receptacle fitted with a false slatted bottom 
and covered with coarse cotton or linen cloth, 
through which the whej^ can easily escape. When 
the time comes for separating the whey, so much 
as will run off readilj- is drawn off, and the re- 
maining whey, mixed with particles of curd, is 
dipped into the sink, the whey runs off freely 
through the strainer and slatted bottom, and the 
curd, being spread over the whole surface of 
the sink, soon mats into a solid mass, and the 
piling process goes on the same way as is done 
in the vat. During this process various changes 
take place. The pressure of the particles of curd 
upon one another serves to expel a large part of 
the whey that still remains ; at the same time the 
temperature is kept sufficiently high so that the 
production of lactic acid is not checked. The effect 
of the acid is to cause a series of marked changes 



Grinding. 



181 



in the physical condition of the curd. From the 
condition of a tongh, spongy mass when first ched- 
dared, the curd changes into a smooth, elastic, 
fibrous condition, not unlike the physical appearance 
of well cooked, lean meat. When the curd reaches 
the condition above described it is- ready for the 
next step in the process, and by this time sufiicient 
lactic acid will have developed so that fine threads 
may be drawn out two to three inches on a hot 
iron. 

Period v., grinding. — When the curd is read}^ for 
grinding, the whey has been removed to so great 

an extent that the pro- 
duction of lactic acid 
measurably stops. The 
curd is ground in or- 
der to reduce it to 
particles of convenient 
size for receiving the 
salt and for pressing 
into a solid mass in 
the cheese. The grind- 
ing, or more properly 
the cutting, is done in 
special machines known 

Fig. 25. "Harris" curd mill. t -n r\p ,■, 

as curd mills. Of the 
various styles of mills, those are best which cut 
the curd into pieces of uniform size, without tearing 
it apart, for the reason that when so treated less fat 
escapes and the uniformity of size of the pieces aids 
in the proper and even absorption of the salt by the 




182 



Milk and Its Products. 



curd. After the curd is ground, it is kept sufficiently 
stirred to keep the particles from matting together 




Fig. 26. " MacPherson" curd mill. 

again. A further maturing of the curd takes place, 
during which it takes on a peculiar nutty flavor, 
and the particles of casein begin to break down 

so that the fat may be re- 
moved by pressure. When 
this stage is reached the curd 
is ready for the next step, 
which is salting. 

Period VI., salting. — Salt is 
added to the curd primarily for 
the sake of the flavor it im- 
parts to the cheese, just as 
salt is added to butter: but the 
addition of the salt to the curd 
has a further effect in the pro- 
cess of manufacture. The salt 
makes the curd drier by reason of extracting the 
water for its own solution, and at the same time 




Fig. 27. Seetion of " Pohl" 
cui'd mill. 



Salting and Pressing. 183 

hardens the curd. It also checks the further devel- 
opment of lactic acid. The salt should be uniformly 
mixed through the curd, and the curd kept stirred 
until it is fully dissolved. A salt of rather coarse 
grain is preferable for cheese. It requires a some- 
what longer time for solution, and the particles of 
the salt are carried to the centre of the pieces of 
curd more effectually. When the salt is thoroughly 
dissolved the curd is ready to put in the press. 

During the cheddaring and grinding stage va- 
rious means, as covering with cloths, etc., have 
been taken to keep up the temperature of the (5urd, 
and at the time when the cheese is ready to salt 
it should not be below 90° F. When the salt is 
added the curd should be spread out thin, so that 
it will cool off, and when it is put into the press 
should be at a temperature of from 78° to 82° F. 
If the curd is put in the press too warm, the fat 
is more easily pressed out and lost. On the other 
hand, if the curd is at too low a temperature when 
put in the press, it is more difficult to make the 
particles adhere together into a solid mass. The 
object of pressing the cheese is to bring it into a 
form suitable for transportation and convenient for 
consumption. The pressure also removes any surplus 
moisture that is in the curd ; but the primary object 
of pressing is not to remove moisture. In fact, all 
of the moisture that is removed from the cheese by 
the press is that held by capillarit}' between the par- 
ticles of curd, and practically^ none can be expressed 
from the particles themselves. If the curd is too 



184 Milk and Its Products. 

wet at this stage, it is because care was not taken 
to expel the moisture from the particles of the 
curd in the cooking process, and it cannot be re- 
moved by extra pressure. An ideal condition of 




Fig. 28. " Fraser" continuous pressure gang cheese press. 



the cheese is to so press it that the particles will 
unite together in as nearly as may be a solid 
mass. This will depend, upon the temperature and 
maturity of the curd. If the curd is put in press 
at the stage of maturity corresponding to the 
beginning of the cheddaring period, it will be 
very difficult to cause it to unite in a firm mass ; 
but if it is allowed to mature until the casein 
shows signs of breaking down, and then is not 



Curing. 185 

lower than 78° F., a slight amount of pressure 
will cause the particles to unite in a smooth and 
solid mass. The pressure should be uniform and 
continuous for at least twenty hours. Where a 
screw press is used, care must be taken to tighten 
the screws as rapidly as they become loose, partic- 
ularly for the first hour after the cheese is put in 
the press. Those presses that are fitted with ap- 
pliances for taking up the slack and making the 
pressure continuous show excellent results in the 
texture of the cheese. After the cheese has been 
in the press for three -fourths of an hour it should 
be taken out, turned, the bandage straightened, and 
the whole cheese wiped with a cloth wrung out of 
water as hot as can be borne by the hand. This 
warming of the surface aids in the formation of a 
firm, transparent rind, and it improves the appear- 
ance of the cured cheese. Seamless bandage is 
practicallj' the only kind now used, and it should 
be cut of such a length that it will extend over 
each end of the cheese for an inch and a half or 
two inches ; when the cheese is put in the press, 
circular cap cloths should be put between the ends 
of the cheesfe and the follower. These cap cloths are 
allowed to remain upon the cheese after it is taken 
from the press and while it is curing, and are re- 
moved just before the cheese is boxed for market. 

Period VII., curing. — The green cheese, when 
taken from the press, if exposed to a temperature 
of about 70° in a pure atmosphei'e, undergoes a 
series of fermentations which result in breaking 



186 2Iilk and Its Products. 

down or rendering solnble the casein and in the 
development of the characteristic flavors pecnliar to 
good cheese. These flavors are almost entirely de- 
veloped during the ripening process. The ripening 
is brought about by a series of fermentations that 
goes on in the cheese. It is not well understood 
just what these fermentations are ; but it seems 
evident that at least in the early stages of the 
curing, lactic acid germs are active, although the 
greater majority of these disappear after a short 
time. During the ripening process, oxygen is taken 
up and carbonic acid given off. The qualitj^ of 
the cheese is best when the ripening process goes 
on gradually and continually. The higher the tem- 
perature the faster the ripening will go on ; an 
extreme temperature of 65° or 70° giving the best 
results. At the end of from four to six weeks the 
casein will be so broken down that the cheese is 
fairly digestible and fit for consumption, though if 
kept longer under good conditions the cheese will 
improve for three or four months, and then if kept 
moderately cool, and in not too moist nor too dry 
an atmosphere, it may be kept one or two years. 
During the early part of the curing process the 
cheeses should be turned upon the shelves every day 
until a sufficient amount of water has evaporated, 
so that they no longer tend to lose their shape. 

Difficulties likely to occur in cheddar cheese snak- 
ing. — The chief difficulty in cheddar cheese making- 
comes from the presence in the milk of germs 
which produce fermentations that are undesirable. 



Gassy ' ' Curds . 187 

These fermentations usually begin during the cook- 
ing process, and continue through cheddaring. Or- 
dinarily they evolve a considerable amount of gas, 
causing what are known as floating or gassy curds, 
and are usually accompanied by disagreeable odors 
and flavors. The formation of the gas in the curd 
gives it a sponge -like texture, and when the par- 
ticles of curd are cut across they are seen to be 
full of minute holes, the condition usually denom- 
inated pin-holes. The best means of treating this 
trouble is, of course, prevention; but even with the 
utmost care by makers of experience, milk contain- 
ing the germs of these fermentations will find its 
way into the vat. Ordinarily these fermentations do 
not work with the lactic fermentation ; each hin- 
ders the action of the other so that the chief means 
of overcoming the difficulty of gas or pin-hole 
curds is to favor in every way possible the pro- 
duction of lactic acid. To this end the milk is 
well ripened before the rennet is added, and the 
heat is raised as rapidly as possible to a higher 
temperature of cooking than ordinarily is used. In 
extreme cases the curds may be heated as high 
as 104° F. After the whey has been drawn great 
care is taken to keep the temperature of the curd 
from falling, and at the same time the escape of 
the gas is favored by frequent turning and piling 
of the curd. Where the curds are gassy the ched- 
daring process must be continued until the formation 
of gas has ceased and the holes in the curd have 
collapsed. In extreme cases, where the gassy curds 



188 3Iilk and Its Products. 

have produced very strong, undesirable flavors, these 
may be removed by drenching with hot water. The 
means used to prevent the development of gas, and 
to get rid of the gas alreadj^ formed, ordinarih' favor 
the escape of fat from the cheese, so that while the 
bad effects of the gassy curd may be largely elimi- 
nated from the finished cheese, still it is always done 
at the expense of a certain loss of fat. 

Another difficulty that often confronts the cheese- 
maker is that coming from the milk arriving in too 
ripe a condition, not necessarily accompanied by un- 
desirable fermentations. In the case of such milk, 
the development of lactic acid is very rapid and the 
curds, technically described, "work fast." When this 
occurs, the production of lactic acid is more rapid 
than the shrinking of the curd, and the whey is 
sufficiently' acid to be drawn off before the curd has 
shrunken down. In this case, the curd should be 
thoroughly and continually stirred after the whey 
is drawn until the whej- has been well worked out 
before the curd is allowed to cheddar ; but where 
it is known at the beginning of the process that 
the milk is over -ripe, care should be taken through- 
out the whole process to use every means to re- 
tard the formation of lactic acid, and at the same 
time to cause as rapid a shrinking of the curd as 
possible. To this end, the milk may be set at a 
lower temperature and a larger amount of rennet 
used, and when the curd is cut it should be stirred 
until the whey has well separated before the heat- 
ing process begins. With care in these particulars, 



Flavor and Texture. 189 

there is slight danger of the formation of acid be- 
fore the curd has shrunken down. 

Qualities of cheese. — A well cured cheddar cheese 
of good quality should have about the following 
composition : 

Per cent. 

Water 34. 

Fat 36.8 

Casein and albumin 25.7 

Sugar, ash, etc. (largely salt) 3.5 

100. 

The characteristic flavors should be well pro- 
nounced but not strong, depending somewhat upon 
the age of the cheese. The flavor should also be 
clean ; that is, free from any flavors due to the 
influence of undesirable fermentations or to foreign 
matters that may have gained access to the milk 
through the food or otherwise. The texture should 
be solid, smooth and firm. When bored with the 
trier, the plug should come out solid, or nearly so, 
and smooth. There should be no moisture visible 
in any part, and no appearance of any separation 
of the fat from the casein. When crushed, the cheese 
should readily break down into a smooth, unctuous 
mass, without indication of the presence of undue 
moisture, and should emit a pleasant, nutty flavor. 
When broken across, the flaky texture should be 
manifest, the so-called "flinty break." The color 
should be uniform, not mottled, and with more or 
less of a tendency to translucence, especially in new 
uncolored cheese. The rind should be smooth, with- 
out cracks, hard and transparent. The bandage 



190 MilJc mid Its Products. 

should extend evenly over the ends of the cheese for 
about two inches and should be straight and smooth. 
The ends of the cheese should be parallel and the 
sides straight. These various qualities are usually 
ranked according to the following scale : 

Per cent. 

Flavor 45 

Texture 35 

Color 15 

Finish 5 

100 



CHAPTER XII. 

OTHER VARIETIES OF CHEESE. 

Slight variations in any of the minor details of 
the cheese making processes have a distinct influence 
on the character of the finished product. A natural 
result of this is that the varieties of cheese are 
almost innumerable. Von Klenze* in his Hand Book 
of Cheese Technology describes no less than 156 dif- 
ferent kinds, whose manufacture is distributed through 
Europe and America. Not onlj^ is the number of dis- 
tinct kinds very large, but the same kind or variety 
varies greatly in character and quality, according to 
the conditions under which it is made. Without at- 
tempting to accurately classify the various kinds of 
cheese, it may be said that they fall roughly into 
about three natural groups or classes. First, those 
whose chief characteristics depend upon the amount 
of water that has been removed in the process of 
manufacture. These we may call hard or soft cheeses. 
Second, those whose distinctive qualities depend upon 
the amount of fat which the cheese contains, whether 
it is the normal amount of the milk, whether a part 
of the fat has been removed, as in the case of 



*Von Klenze, Handbuch der KJiserei-Teehnik, Bremen, 1884. 

(191) . 



192 Milk and Its Products. 

skimmed or partially skimmed cheeses, or whether fat 
has been added to the milk as in the case of the so- 
called cream cheeses. And third, those whose dis- 
tinctive characteristics depend upon the sort of fer- 
mentation to which they have been subjected. In 
the case of many of these, special ferments are in- 
troduced into the cheese during the curing process, to 
bring about the desired characteristics and flavors. 
The details of manufacture upon which the peculiar 
characters depend are, in many cases, so intricate 
and minute that it is practically impossible to so 
describe them that a nvoice might successfully fol- 
low out the directions. The actual practice must in 
most .cases be learned at the hands of an expe- 
rienced teacher. Even as careful a description as 
possible is more than could be attempted here, and 
we shall, therefore, limit our discussion to a few of 
the better known and most largely manufactured 
varieties. The introduction of the so-called fancy 
varieties in America is in its infancy, but is rapidly 
developing, and bids fair to become a most impor- 
tant diversification of the dairy industry. 

American Jiome -trade, or stirred -ctird cheese. — The 
popular consumptive demand of most American mar- 
kets requires a softer and milder flavored cheese 
than the cheddar or export type. This is brought 
about by incorporating a larger amount of water with 
the curd, and by hastening the curing process, and 
not curing it so far as is ordinarily done with a well- 
ripened cheddar. The details of the manufacture of 
the American home -trade and the American cheddar 



''Home-Trade,^^ or '' Stirred- Curd. ^^ 193 

or export are in the main similar. In fact, the two 
processes merge into one another in such a waj^ that 
we find a regular gradation in the cheese from the 
softest, mildest, short -keeping stirred -curd cheese on 
the one hand to the most solid, long -keeping Ched- 
dar on the other. The distinctive diiferences in the 
two processes of manufacture are that in the home- 
trade cheese, after the whey is drawn from the curd, 
the curd is not allowed to mat into a mass or Ched- 
dar, but is kept stirred in such a way that the whey 
will drain off until it is dry enough so that the par- 
ticles of curd will not unite. It is then salted and, 
with more or less further maturing of the curd, is 
pressed and cured. The character of the resulting 
cheese, however, depends quite as much upon the 
amount and character of the changes that go on in 
the curd after the whey is drawn, and before it is 
put into press, as upon the mere fact of allowing it 
to pack in a mass (cheddar) or keeping it apart by 
stirring. If the cheddar variety is ground shortly after 
matting, and immediately salted and put to press, 
the resulting cheese will resemble the stirred -curd 
type. ,0n the other hand, if the stirred -curd is kept 
warm and frequently stirred, many of the same 
changes will go on as in the cheddared curd, and 
the cheese when cured will resemble the cheddar 
type. 

Another distinction between the two processes is 
that in the case of the cheddar cheese the aim is to 
get rid of all the water consistent with a compact 
union of the particles of casein. In the manufac- 



194 Milk and Its Products. 

ture of the stirred -curd cheese, on the other hand, 
the aim is to retain as much water as possible 
without having it appear in the form of free water in 
the cheese. To this end, in the stirred -curd process 
those influences which tend to contract the curd, 
namely, the application of heat and the development 
of "lactic acid, are not carried so far as in the Ched- 
dar process. In fact, in many cases they are not car- 
ried far enough to remove all of the water necessary, 
and some remains in the cheese, making a ''wet," 
sloppy " or " leaky" cheese. 
Because of the larger amount of water it contains, 
this kind of cheese is profitable to the producer of 
the milk and to the manufacturer, and when properly 
made and carefully cured, it may be of excellent 
quality, being mild, creamy and soft ; but largely, 
too, because of the large amount of water contained 
in it, it is easily subject to decomposition changes, 
goes off flavor rapidly, and does not bear transporta- 
tion well. 

Sage cheese. — In many parts of the United States 
this cheese is very popular for local consumption. 
Its manufacture is not different from the ordinary 
type of cheese, either cheddar or stirred -curd, but 
an infusion of sage leaves, or sage extract (in which 
latter case the green color is secured by an in- 
fusion of fresh leaves of any inert plant, as clover, 
green corn, etc.), is added to the milk before the 
rennet coagulation, and imparts a light greenish 
color and characteristic flavor to the curd. Ordi- 
narily, where sage cheese is made, the sage is added 



Young America and Neufchatel. 195 

to onh- a part of the milk, and two separate curds 
are manufactured simultaneously, and mixed together 
as they are put in the press, resulting in cheese of 
a mottled green color. 

Young America, pineapple, truckle cheese. — These 
are names applied to various forms of small cheeses. 
The truckle and Young America cheeses in particular 
are small cheeses of the cheddar or other common 
type, pressed in sizes of six to ten pounds weight. 
The pineapple cheeses are pressed in shapes sug- 
gested by their name, and are generally made as 
firm and solid as possible. 

American NeufcJiatel cheese. — This is a soft cheese, 
made in imitation of the imported Neufchatel, as 
follows : The room in which the cheese is made 
must have a uniform temperature of 70° F., night 
and daJ^ The milk, pure, sweet and well aer- 
ated, is warmed to 82° F., and 2% ozs. of com- 
mercial rennet extract added per thousand pounds of 
milk. The rennet is stirred into the milk with a 
circular motion for ten minutes. The vat is then 
covered and the milk allowed to stand until the curd 
has formed and so shrunken that about half an inch 
of whey covers the curd. The curd is then removed 
and placed in cloth strainer bags until the whey 
has drained off. It is then pressed for twenty -four 
hours. When taken from the press it is worked 
and kneaded until it is of a homogeneous texture. 
During the working 1% per cent of salt is added. 
It is then molded in small round tin molds, 2% 
inches long by 1% inches in diameter, and wrapped 

N 



196 3Iilk and Its Products. 

first in paper and then in tin foil, when it is ready 
for sale. Carefnlly made in this way, it will keep 
for two to fonr weeks, according to the amount of 
moisture it contains. 

Philadelphia cream cheese. — This is a soft cheese 
growing in popularity in proximity to many of our 
larger markets. It resembles the Neufchatel, but is 
made of cream, and is put up in different form. The 
details of its manufacture are as follows : The tem- 
perature of the room is quite as important as in the 
manufacture of Neufchatel, and should be uniformly 
75° F. The milk is warmed to 70° F. and run 
through a separator, taking out 50 per cent as 
cream. This cream is heated to 84° F., and 4% 
ozs. of rennet extract added per thousand pounds of 
cream. The rennet is stirred in with a circular mo- 
tion for fifteen minutes, after which it is allowed to 
stand until whey can be seen around the sides of 
the vat. It is then drained, pressed and worked 
in the game Avay as Neufchatel, except that twenty 
hours' pressing is sufficient, and more salt (3 per 
cent) is used. It is molded in flat, thin cakes 3x4 
inches, in a flat tin mold, wrapped in parchment 
paper, and packed for shipment. 

Some of the older writers describe a cream cheese 
made by simply draining and lightly pressing in 
square blocks a thick cream obtained by setting milk 
in shallow pans, heating over water till the cream 
" crinkles," and setting in a cool place for tw^elve to 
twenty -four hours. 

Limhurger . — The Limburger is one of the varieties 



Lhuhurger, 197 

of cheese whose characteristics are due to specific 
fermentations brought into the cheese during the 
ripening process. These fermentations result in a 
well known putrefactive odor and pungent flavor. 
According to Monrad,* the manufacture of Limburger 
in America and Europe is not greatly different. Or- 
dinarily the cheese is made from whole milk, but 
frequently skimmed or partly skimmed milk is used. 
In Europe the copper kettle is commonly employed ; 
in America both the kettle and the ordinary rectan- 
gular cheese vat are used. In the latter case the 
curd is made in much the same way as for ordinary 
cheese up to the point when the whey is drawn off. 
The milk is set at a rather high temperature (92° to 
100° F.). The curd is broken into pieces the size 
of a hen's ^gg, and allowed to settle to the bottom 
of the kettle. It is then scooped out and put in 
rectangular molds arranged on tables, so that the 
whey ma}' drain off. The molds are carefully turned 
till the whey has measurably ceased running, and the 
cheeses will maintain their form. They are then 
placed in rows on a flat table with thin pieces of 
board between them, and subjected to light pressure 
from the sides. The cheeses are turned frequently at 
first, and then at longer intervals, till at the end of 
thirty -six to forty -eight hours they ma^' be taken 
from the press. They are then salted by rubbing 
salt on the ends and flat sides for three or four 
days. After the first salting they are laid on the 
table in single layers, afterward they are piled, at 



* Cheese making in Switzerland. Wiuuetka, lU., 1896. 



198 Milk and Its Prodticfs. 

first two deep, then three or four deep, so that the 
absorption of the salt may be promoted. During 
salting and pressing they are kept at a uniform tem- 
perature of from 59° to 63° F. They are then cured 
in a cool (60°F.), well ventilated cellar nearly satura- 
ted with moisture, with careful watching and much 
manipulation and turning. With the ripening they 
begin to soften. The curd, at first hard, takes on 
the characteristic glass3% greasy appearance, at the 
same time that the rind becomes at first yellow then 
reddish yellow. The softening begins on the outside 
and proceeds toward the center, and the cheeses are 
considered to be marketable when one -quarter of the 
cheese has taken on its characteristic texture. 

Imitation Siviss cheese. — A considerable amount of 
cheese closely resembling the true Emmenthaler is 
made in America. Its main distinctive characteristic 
lies in its peculiar flavor, and in the appearance of 
the peculiar so-called Swiss holes in its texture. 
Both of these are due to specific fermentations, 
which take place in the cheese during the curing 
process. (See Emmenthaler cheese, page 200.) 

These are the principal varieties of cheese that 
are manufactured to any large extent in America. 
There are, however, a number of brands of cheese 
upon the market that may properly be classed under 
the general name of 

Prepared cheese. — These fanc}' brands are in gen- 
eral made from an ordinary cheese of good qual- 
ity, by removing the rind and reducing the remainder 
to a homogeneous, more or less pulpy, mass. To this 



Stilton. 199 

is added a certain amount of additional fat, either in 
the shape of butter or other fat, and some flavoring 
matter in the form of cayenne pepper, brandy, or 
something of like nature. The cheese is then packed 
closely in fancy glass or earthenware packages, sealed 
tightly, and marketed. The names under which it is 
sold vary with the manufacturer and with the recipe 
under which it is made. Many of them are sold 
under registered trade -marks. Some of the better 
known are Club House, Meadow Sweet, Canadian 
Club, etc. 

Among the varieties of cheese of foreign manu- 
facture, the following are worthy of mention: 

English cheeses. — The various dairy localities in 
England produce cheeses bearing their distinctive 
geographical names. In the main, thej' are of the 
cheddar type, and differ from the true cheddar only 
in details of manufacture and in slight differences 
in texture and flavor, in much the same way that 
the American home -trade cheese differs from the 
American cheddar. Of the English cheeses, the best 
known are the English Cheddar, single and double 
Gloucester, Cheshire and Wiltshire. 

One English cheese in particular is worthy of a 
little more extended notice. It is the well known 
Stilton. 

Stilton cheese. — Stilton cheese is a rich, rather 
soft, mild flavored cheese, more or less impregnated 
with threads of blue or bluish green mold, Avhich to 
a greater or less extent mask the flavor. In making 
Stilton cheese, more or less of the cream of the 



200 Milk and Its Products. 

night's milk is added to the morning milk. The 
later practice is to use less cream than formerly, 
and in some cases no cream at all is used. The 
curd is coagulated and cut in the ordinary man- 
ner, but little heat is used in expelling the whey, 
and it is gotten rid of by draining the curds on 
draining tables and afterward in cloth strainers with 
light pressure. The cheeses are pressed in small sizes, 
ten to fifteen pounds, and slowlj^ cured, sometimes for 
two or three years. The veins of mold have come to 
be esteemed so characteristic of Stilton cheese that 
their production is assisted by inserting in the ripen- 
ing cheese wooden skewers that have been smeared 
with crumbs of old cheese fully impregnated with the 
mold. 

Emmenthaler, Gruyere, Swiss or Scliweiizer. — The 
cheese made in the mountains of Switzerland has a 
historj^ reaching back to the seventeenth century,* 
and many of the old customs are still used ; but, as 
might be expected, the various localities have devel- 
oped many varieties of this general type, in the same 
way that the different forms of cheddar and allied 
cheese have come to differ from one another. It is 
generallj" considered that the cheese known as Em- 
menthaler is typical of the whole group of Swiss 
cheeses. The Emmenthaler cheese is made in a 
large copper kettle instead of a vat, and ordinarily the 
curd made in one vessel is pressed as a single 
cheese. After the curd has been coagulated with ren- 
net, it is broken up in various waj^s into small pieces 



* Monrad, Cheese making in Switzerland. Winnetka, 111., 1896. 



Swiss and Edam. 201 

as nearly uniform in size as possible, and then heated, 
with careful stirring and attention, up to 135° or 
140° F. After heating, the curd is allowed to sink 
to the bottom of the vessel in a solid mass, and 
while in this condition the bandage is slipped around 
it and the whole mass of curd conveyed to the 
hoops, where it is pressed. In the subsequent curing 
the curd is usually salted from the outside of the 
cheese as it is curing, and during the curing pro- 
cess certain fermentations go on which produce large 
holes in the cheese. These holes in perfect cheese 
should be uniform in size and at equal distances from 
one another. The casein itself breaks down into a 
cheese of solid, uniform texture and characteristic fla- 
vor. It has been asserted that the characteristic fla- 
vors of the Swiss cheese are due to the character of 
the Alpine pastures upon which the cows feed, but it 
is altogether likely that the curing fermentations have 
as much or more to do with developing these flavors. 

Edam. — This cheese is made in Holland, and is 
pressed in round balls of four to six pounds weight, 
which, when ready for shipment, are colored red with 
annatto or beet root and wrapped in tin foil. Edam 
cheese is made from milk not very rich in fat. Often- 
times partially skimmed milk is used, and in other 
cases a considerable amount of fat escapes in the 
whey during the process of manufacture. The curd 
is made very dry and the curing process is rather 
slow, so that the resulting cheese is verj^ hard, and 
will keep unchanged almost indefinitely ; but while 
it is hard, the curd is thoroughly broken down by 



202 Milk and Its Products. 

the curing process, and is readily soluble and di- 
gestible. 

Gouda. — This is a cheese resembling the Edam in 
general type, and also made in Holland, but not 
quite so hard, and somewhat approaching a well 
made cheddar in general texture. It is larger than 
the Edam, weighing from ten to fifteen pounds. 

Roquefort. — This is a soft or semi -soft cheese, 
made in France. In some respects it is the most fa- 
mous of all varieties of cheese. It is sometimes made 
from goats' as w^ell as cows' milk, and it has peculiar 
characteristics imparted hj specific fermentations that 
are brought about in the curing process. The curing 
is done in caves in limestone rock, Avhere the air is 
uniform in temperature, and in order to bring about 
the desired fermentations the germs are added to the 
curd in the process of manufacture. These germs 
are often cultivated upon bread or similar substance, 
and this, crumbled up, ' is mingled with the curd 
in order to insure the proper fermentation in the 
cheese. Roquefort cheese, when well made and 
cured, is of a rather soft texture, and the whole 
mass is permeated with the molds, imparting a 
characteristic flavor to the cheese. 

Brie. — Another soft French cheese. The milk is 
put into small, circular vessels and the rennet added. 
The curd is allowed to remain until it has become 
sufficiently firm to be removed from the whey in one 
piece. It is then carefully taken up and put in 
such a position that the whey may drain from it. 
It is turned frequently and carefully until sufficient 



Roquefort and Brie. 203 

whey has drained away so that the cheeses will 
maintain their form. Thej' are then lightly salted 
and put away to cure. During the curing process 
molds develop on the outside, but the fermenta- 
tions that go on upon the inside of the cheese re- 
sult in the breaking down of the casein into a 
creamj' mass of a strong, piquant flavor. The molds 
upon the outside give to the cheese a strong odor 
of decomposition . 

Gamemhert. — This is still another French cheese, 
YQvy closely resembling the Brie, and differing from 
it only in details of manufacture. 

Gonjonzola. — An Italian cheese, somewhat resem- 
bling Roquefort. 

Parmesan. — A very hard Italian cheese, made 
from milk with very little fat, and from which a 
large part of the water has been expelled. In curing 
it takes on a rather sharp flavor, and naturally it 
can be kept in almost any climate for almost any 
length of time. It is so hard that it is ordinarily 
grated before being used, and is almost wholly 
used to add piquancy to soups, sauces, and the 
like. 



CHAPTER XIII. 
BY-PRODUCTS OF THE DAIRY. 

The by-products of the dairy are skimmed milk, 
buttermilk and whey, and a variety of products 
that maj' be manufactured from them. The utiliza- 
tion of these by-products to the best advantage is 
an important part of the economy of dairy manu- 
facture. 

Skimmed tuillx, hiitfertnilk and whey. — By far the 
larger part of the dairj^ by-products must of neces- 
sity be utilized as food for animals, either because 
of the cost of transportation or for lack of facility 
in marketing many of the rather perishable products 
that can be made from them. All of these products 
make a valuable food for animals, of course in pro- 
portion to the amount of the normal constituents of 
the milk which they contain. Whey is less valuable 
than skimmed milk or buttermilk, because it has lost 
the greater part of its casein as well as fat, but 
it still is of sufficient value to render its utilization 
of importance. Naturallj', we expect that young ani- 
mals (calves and pigs) will thrive the best upon 
these products, though skimmed milk has frequently 
been fed to cows with good results. All three are, 
however, so bulky that some more concentrated food 

(204) 



Milk Sugar. 205 

should be fed in connection with them, if they are 
used to the best advantage. When economically 
fed to 3'oung pigs and calves, skimmed milk and 
buttermilk may be made to return about fifteen cents 
per hundred weight, and whey about one- third less. 
These products are of value for food in proportion 
as the milk sugar has not been changed to lactic 
acid. They may be fed in unlimited quantities with- 
out ill results upon the health of the animal, ex- 
cept that occasionallj' when the milk is very sour, 
or when fermentations other than lactic have set 
in, derangements of the digestive organs, diarrhoea, 
etc., sometimes occur. It is, therefore, advisable that 
all of these products should be fed in as fresh a con- 
dition as possible, and it has been found in many 
instances that the custom of sterilizing or partially 
sterilizing the skimmed milk or whey at the factory, 
by injecting a jet of steam into it until the whole 
is heated up to about 180° F., is practical, and is fol- 
lowed by beneficial results. 

Milk sugar. — Milk contains between 4 and 5 per 
cent of milk sugar, and the manufacture of this sugar 
has come to be an important industry. In the manu- 
facture, whey is preferably used, or if skimmed milk 
the casein is first coagulated and removed. The 
water is then removed by evaporation until the crys- 
tals of sugar are formed. Various methods are used 
to rid the sugar of albumin and other materials con- 
tained in the whey. Formerly this was a somewhat 
difficult operation, and added considerably to the ex- 
pense of the manufacture, but recently improvements 



206 Milk and Its Products. 

have been made in this respect, so that the cost of 
the manufacture of the sugar is much lessened. The 
growth of the industry has been very rapid, result- 
ing in a much lower price for the product and a very 
much increased consumption. Formerly, almost the 
only use of milk sugar was medicinal. Noav, be- 
cause of its digestibility, it forms an important in- 
gredient of many of the so-called infants' and inva- 
lids' foods. It is usually prepared in the form of a 
white crystalline powder, only mildlj' sweet to the 
taste. 

Butch cheese {cottage cheese, schmierJiase, pot cheese, 
etc.). — A toothsome and nutritious article of food is 
made from sour skimmed milk or buttermilk by al- 
lowing the casein to coagulate by the action of lactic 
acid already formed, and then expelling the water by 
the aid of heat. A considerable number of products 
locally distinct, and differing in the degree of drj'ness 
of the casein, are made in this w^ay, the general pro- 
cess of manufacture being to take sour buttermilk, or 
skimmed milk which has coagulated, heating gentlj^ to 
from 85° to 125° F., according to circumstances, drain- 
ing off the whey through a cloth strainer, and then 
reducing the texture of the resulting curd by knead- 
ing with the hands or a pestle ; salt is added, and 
the product is improved by the addition of a small 
amount of cream or butter, and occasionally by the 
use of some of the more common spices, as nutmeg, 
caraway, etc. It is largely made only for domestic 
consumption, but in most cities and villages, es- 
pecially during the summer months, there is a con- 



Prhnost — Cheese Food. 207 

siderable demand for fresh cheese of this sort, and 
its manufacture is often a source of revenue to fac- 
tories suitably located. It is usually sold and eaten 
in a fresh state, but it may be subjected to cer- 
tain curing processes, which quite materially change 
its character, and which vary widely in different lo- 
calities. 

Whey cheese {primost and myseost) . — These are pro- 
ducts manufactured from whey in some of the north 
European countries and among the Scandinavians in 
our own. They are really forms of evaporated whey 
and, according to Monrad,"^ are made somewhat as 
follows : The whey, not too sour, is boiled in a 
suitable vessel under a slow fire, care being taken 
that it is not scorched or burnt ; when the albumi- 
nous matters are coagulated they are removed to facil- 
itate evaporation, and the evaporation is carried on 
until the Avhole mass assumes a syrupy condition; 
the albuminous matters are then returned to the 
condensed whey, the whole is removed from the fire 
and mixed rapidlj' until in the form of a thick 
nnish ; some cream is then added and the material 
pressed in brick shaped moulds, and after a day or 
two is ready for market. It is practically unknown 
except in those districts where the Scandinavian 
population is large. 

Cheese food. — Within the last few years an en- 
terprising cheese -maker, Mr. J. J. Angus, of Wiscon- 
sin, has perfected a system of manufacturing what 



*A B of Cheese-making. Winnetka, 111. 1889. 



208 Milk and Its Products. 

he calls a complete cheese food. It is simply a pro- 
duct containing all the constituents of the milk in 
a condensed form. An ordinary cheddar cheese is 
first made and cured ; the whey is evaporated to a 
syrup3^ consistency, and the cheese from a corre- 
sponding amount of milk is ground down to a pasty 
consistency and mixed with the evaporated whey. 
The resulting mass is pressed into cakes of conve- 
nient size, and under ordinary conditions will keep 
a long time. The cheese food is a soft, homoge- 
neous substance of a mildly cheese -like, sweetish 
flavor. 

Wheyn. — Quite recently there has been patented 
in this country by Alexander Bernstein, of Berlin, 
Germany, a nourishing, mildly stimulating drink Avith 
the above name. It is, according to the specifications 
of the letters patent, a sour, sterilized whey, from 
which the albuminous matter and fat have been re- 
moved. It is put up without further treatment, or it 
may be flavored with hops or other material, which 
may also be carbonated, or subjected to a mild alco- 
holic fermentation. 



CHAPTER XIV. 
BUTTER AXD CHEESE FACTORIES. 

Location of creameries. — In the location of a 
creamery no one thing is more important than to 
secure a well drained site, and yet this is in many 
cases evidently the last thing thought of. Cream- 
eries are located in any out of the waj' corner or 
bit of waste land that happens to be at hand. 
The drainage is no less an important matter to be 
considered in selecting a creamery site than in se- 
lecting a house site. The foundation of cleanliness 
in a cr,eamery begins with the sewer, and unless 
the waste materials can be completelj^ and quickly 
drawn away the labor of keeping the whole prem- 
ises clean is very much enhanced. 

Other things being equal, then, elevated ground 
should be selected as a proper site for a creamery, 
and if the advantage of the elevation can be made 
use of in the arrangement of the working rooms, 
so much the better. Another matter that may prove 
of considerable value in many cases is a regard for 
the natural or artificial shelter that maj^ be given the 
creamer^' building. A difference of six or eight de- 
grees in the work-room temperature may be easily 
secured by having a due regard to the advantages of 

(209) 



210 



Milk and Its Products. 




shade from groves or the channels of natural air 
drainage. On the other hand, it is not well to lo- 
cate the building on a too bleak or exposed site, and 
yet the great majority of creameries are either ex- 
posed to the 
full rays of 
the August 
sun or to the 
bleak winds of 
winter. 

A rrang e- 
ment of build- 
in g. — Two 
general princi- 
ples govern 
the arrange- 
ment of cream- 
ery buildings. In the one, the milk is taken in at such 
an elevation that it may flow by gravity from the 
weighing can to the receiving vat, thence to the tem- 
pering vat, thence t-o the separator, and finally to the 
skimmed milk and cream vats. In the other, the milk 
is taken in on a level with the work-room floor, and 
is elevated b}^ pumps. Both plans have their advan- 
tages and disadvantages. The main advantage of 
what may be called the " gravity" system is, that 
the milk flows by its own weight during the whole 
course of manufacture, and no pumps, troublesome 
to keep clean, are necessary. As an offset to this 
advantage, it entails a considerable amount of ex- 
tra labor in ascending and descending the neces- 



Fig. 29. Diagram of creamery arranged iipoii the 
"gravity"' plan. 



Arrangement of Creameries, 



211 




saiy stairs or steps. The pumping system, on 
the other hand, is economical of labor, but intro- 
duces one or 
more pumps, 
through which 
the milk must 
be passed, and 
which are al- 
ways, even 
when of the 
simplest pat- 
tern, more or 
less difficult to 
keep clean, 
and exceeding- 

Fi^. 30. Diagram of creamery arranged upou tlie ly liable tO bc 
' pumping" plan. ^ , -, x 

neglected. In 
the outline diagrams is a creamery arranged ac- 
cording to either system. By reference to the ground 
plan (Fig. 31, page 212), it may be seen that in 
either case the amount of floor space required is the 
same. In Fig. 29 is shown the elevation under 
the "gravity" arrangement, with the exception that 
the skimmed milk vat is shown elevated. Here the 
milk is taken in at A, passes to B the receiving 
vat, thence to C the tempering vat, thence to D the 
separator, thence to E the cream vat, and through 
the pump H to F the skimmed milk vat. In the 
pumping system, Fig. 30, the same letters indicate 
corresponding parts. It will be seen here that the 
milk is pumped through G from B to C. Referring 



212 



2Tilk and Its Products. 



again, then, to the floor plan, if the arrangement be 
according to the pumping system, the operator, stand- 




Fig. 31. Ground plan of creamery in Figs. 29 and 30. A, weighing can ; B, 
receiving vat ; C, tempering vat ; J), separator ; E, cream vat ; J, churn ; 
K, butter worker; L, cold storage room ; M, office ; ^.boiler room ; O, fuel. 

ing near his scales and receiving vat A, is but a step 
from the separator D and the l^oiler N, and can easily 
give attention to all parts of his factory. Whereas, 
if the creamery is arranged upon the " gravity " 
plan, he must be constantly ascending and descend- 
ing a series of steps between A and D. It would 
seem, therefore, that when the factory is to be a 



Arrangement of Creameries. 213 

large one, requiring the services of more than one 
man, that the "gravity" system is preferable, be- 
cause of doing away with the objectionable pumps. 
Whereas, if the factory is to be a small one, and 
one man is to do all the work, the amount of 
labor saved by the more compact pumping system 
will more than overbalance the objection arising 
from pumps. In a factory of the size indicated, 
handling from three to five thousand pounds of 
milk per day, a floor space of about 18 x 24 feet 
will be required. In larger factories, it will be 
found of advantage, in controlling the temi3erature, 
to introduce partitions, so that the receiving and 
separating room may be separated from the churn- 
ing and working room, and if much butter is to 
be made up into prints, a third, colder room, for 
printing the butter, will be found of great advan- 
tage during the warm part of the jear. Here, too, 
the question of labor again comes into play. When 
the creamery is so small that all the work is done 
by one man, labor is economized by having all the 
operations conducted in one room, but where two or 
three, or even more men are emploj^ed, it will be 
found of advantage to have separate rooms for the 
different operations. 

Construct ion. — The building should be laid upon 
solid foundation walls rather than upon piers. 
Besides adding decidedh' to the appearance of the 
building, it aids materially in keeping the build- 
ing warm in winter and cool in summer. In regard 
to the floors, cement floors are the most expensive 



214 Milk and Its Products. 

and tlie most durable, and if well laid and com- 
posed of the best materials, are entirelj' satisfactory. 
But wooden floors, tiglitly laid upon a well -drained 
foundation, are fairly durable, and when out of re- 
pair may be easily replaced at comparatively small 
cost. Whatever the floors, they must be thor- 
oughly sewered. The floor should slant rapidly 
to the gutter, so that all water will quickly run 
oif through a thoroughly trapped ii'on pipe until the 
outside of the building is reached, after which 
well -glazed sewer pipe may be used. An abundant 
suppty of pure water is indispensable. This, under 
ordinary conditions, will be obtained from a well, 
A bored or driven well is less liable to contami- 
nation than an open dug well, but in any event 
the site of the well should be chosen with due 
regard to possible sources of contamination. If 
the water is very abundant and at a temperature 
below 48°, a supplj' of ice is not indispensable, 
except for cold storage purposes, but it will be 
found in most cases to be of great advantage. 
In any event, the means of readily securing and 
maintaining in the cream a temperature of 50"" F. 
or below is indispensable. Water and steam pipes 
should be carried to all parts of the building where 
their presence may be of advantage for cleaning- 
purposes. 

The superstructure ma^' be as elaborate or as 
simple as desired. At the least, it should offer as 
good protection from the elements as a well-built 
house does, lu fact, the construction need not 



Arrangement of Cheese Factories. 



215 



differ from that of ordinary house construction, 
except that ceiling on the inside take the place of 
plaster. 

The inside finish should be of matched and 
planed lumber, thoroughly protected with hard oil. 



fe) 







-D- 


c 









Fig. 32. Plau of cheese faetoiy properly arranged 

It should be needless to saj- that the outside should 
be neatly and tastefully painted, yet well -painted 
creameries are the exception and not the rule. 

Cheese factories. — All that was said in regard to 
the location of creameries applies with equal force 
to cheese factories. Heretofore, perhaps, even less 
attention has been paid to the drainage of cheese 
factories than to creameries, but it is quite as neces- 
sary. The arrangement of the cheese factor}' is con- 
siderably simpler than that of the creamery, and mis- 



216 



Milk and Its Products, 



takes in arrangement are less liable to be made. 
The governing principle slionld be that the milk, in 
its transformation from milk to cheese, should pass 



F 
1 1 






















C 


^ 
















B 














-B- 
















B 




B 




B 








E 






































( 


^ 




















T 













Fig. H3. Plan of cheese factory improperly arranged. 

in one direction from the weighing can toward the 
curing room. The outlines given, Figs. 32 and 
33, show factories properlj^ and improperly arranged 
In Fig. 32, the milk taken in at A passes into the 
vats at B, from thence to the curd sink C, and the 
press D, and finally to the curing room E, con- 
stantly in one direction and with a minimum of hand 
labor. Whereas, in Fig. 33, following the same let- 
ters, the milk or curd travels from one end of the 
room to the other and back again. While cheese 
factories, as a rule, are used only during the warm 
months of the year, and perhaps for that reason 



Curing Rooms. 217 

may be less warmly built, still it is not sufficient 
that the superstructure be merely of siding nailed 
to the joists, leaving the inside bare. While, per- 
haps, it is not necessary that the outer siding be 
double, or that building paper be used upon the 
joists, still the joists should always be ceiled upon 
the inside and the ceiling neatly finished in oil. 
The construction of the curing room is the most 
important part of the cheese factory. Here the 
construction should be of such a nature that a 
fairly constant temperature may be maintained. This 
can hardly be secured unless the building is covered 
on the outside with two thicknesses of boards, with 
paper between and tightly ceiled upon the inside. 
This part of the factory, at least, should always be 
upon a solid wall foundation. Constructed in this 
way, if care is taken to ventilate the building thor- 
ouglil}' at night, and to close it tight during the 
day time, a fairly cool curing room can be secured 
even during the hottest weather ; but the temperature 
can be much more satisfactorily regulated if the ven- 
tilation comes through a sub -earth duct for a con- 
siderable distance. This may be arranged by laying 
a three or four -inch glazed sewer pipe at least four 
feet deep, from a point on the surface fifteen or 
twenty rods from the building, and opening into 
the center of the curing room through the floor. 
If the mouth of this sub-earth duct can be placed 
in such a position that the prevailing winds will 
blow toward it, a circulation of cool air can more 
easily and certainlj^ be secured. 



218 Milk and Its Products. 

Combined butter and cheese factories. — The connec- 
tion between the butter and cheese markets is such 
that it is coming to be of considerable advantage 
for a factory to be able to make either butter or 
cheese. In many cases but little additional room or 
expense is necessary. If in the creamery the receiv- 
ing vat is of the same construction as an ordinary 
cheese vat, that is, piped so that hot water or steam 
can be introduced around it, all that is necessary in 
order to make cheese is to add a cheese press and 
the necessary curing room. In a cheese factory the 
addition of a separator, churn and worker serves to 
transform it into a creamery. It is true that the 
presence of the necessary equipment is always a 
temptation toward the making of skimmed milk cheese 
during a part of the 3'ear, but a due regard for the 
reputation of the products of the factory will always 
result in making either full cream cheese or butter 
alone. Naturallj' the manufacture of cheese is most 
advantageous during the summer months, and the 
manufacture of butter most profitable during the 
winter months. It is not at all unlikely that dairy 
manufacture will tend in this direction in the future, 
instead of certain localities being devoted almost ex- 
clusivelj' to butter manufacture and others to cheese 
manufacture, as in the past. 

Farm dairy buildings. — Heretofore the farm dairy 
work has shared with the other farm industries and 
the domestic life the room necessary to its prosecu- 
tion, and this has been and still is a main reason 
for the general inferiority of farm dairy products. In 



Farm Dairy Buildhujs. 219 

order that the farm dairy be successful, it is neces- 
sary that some certain place be set aside rigorously 
for its i)rosecution. The dairy cannot be associated 
with the kitchen, the vegetable cellar, or any other 
part of the farm buildings except to its own detri- 
ment. The room or building devoted to the farm 
dairy need not be large nor elaborate. It should 
simply secure a room of convenient size, shut off 
from any other occupation, well lighted, well venti- 
lated, well drained, and reasonably cool in tempera- 
ture. It is entirely possible that this room be a 
part of the house cellar, but if so it should have 
its own individual exit, and be completely shut off 
from the cellar at large. In the same way it may 
be a part of any of the farm out -buildings, or it 
may be a building by itself. As to whether in a 
moderate sized dairy, where say twenty to forty cows 
are kept, the dairy should have a building separate 
from others or not, depends largely upon the way 
in which the dairj' work is carried on. If the dairy 
is so large that power is required for the churning, 
or if the cream is raised by a gravity process, it 
will undoubtedly be of advantage that the dairy 
should occupy a separate building ; but if the cream 
is separated by centrifugal process, and power is not 
required for churning, then the milk may be sepa- 
rated in the barn adjoining the stable, and only the 
cream carried to the dairy room proper. There are 
many advantages in this latter plan. In the first 
place, the labor of carrying the milk to the dairy, 
and the skimmed milk and buttermilk away, is done 



220 Milk and Its Products. 

away with. In the second place, the room required 
for ripening the cream and churning the butter is 
very small, even for a dairy of considerable size, and 
may easily be fitted up in a cool corner of the 
cellar. The only disadvantage is that steam for 
cleaning the utensils is not conveniently at hand, 
but the advantages in most cases will outweigh this 
single disadvantage. If this requisite of the farm 
dairy building or apartment is secured, namely, a 
room devoted to nothing but butter or cheese manu- 
facture — light, auy and well drained — there is no 
reason why the very highest quality of products 
should not be made under such conditions, and 
there are several reasons why a better product can 
be made than under the ordinary factory conditions, 
where the production and care of the milk is in the 
hands of a large number of persons, over whom the 
butter -maker or cheese -maker can at best exercise 
only partial control. 



CHAPTER XV. 

STATISTICS AND ECONOMICS OF THE DAIRY 
INDUSTRY. 

The dairy industry in its development has fully 
kept pace with other industries and with the pop- 
ulation. The total number of milch cows has in- 
creased between two and three fold since 1850, 
though in 1890 there were slightly fewer cows in 
proportion to the population than in 1850. But while 
the number of cows has not increased faster than the 
population, their product has materially done so. 
This is seen in the average yield per cow and in 
the increase in the production of butter and cheese. 
In 1850 the average yield per cow was 166% gallons. 
This had increased in 1890 to 315.4 gallons, or 
nearly 100 per cent. The total production of butter 
was nearly four times as much in 1890 as it was in 
1850, and the production of cheese slightly less than 
2% times as much. 

The various details of this development are well 
shown in the following tables, compiled from the 
United States Census reports by the Dairy Division 
of the United States Department of Agriculture :* 



*U. S. Dept. Agr., Bureau of Animal Industry, Bulletin No. 11 (Dairy 
No. 1). 

(221) 



999 



il////i' and Its Products. 



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statistics of Production. 223 

Value of principal farm products of the United States. 







1859. 


1879. 


1889. 


Products. 


Per 
cent. 


Total value. 


Per 
cent. 


Total value. 


cent. Total value. 


Meats 




17.9 
21.6 

9.1 
14.4 

7.5 
12.6 

4.5 
12.4 


$300,000,000 
360,680,878 
152,671,168 
240,400,580 
124,635,545 
211,516,625 
75,000,000 
206,6.39,527 


22.1 
19.2 
11.3 
10.8 
12 

7.5 

5 
12.1 


$800,000,000 
694,818,304 
409,505,783 
391,131,618 
436,968,463 
271,636,121 
180,000,000 
440,438,3.53 


23.9 $900,000,000 
15.9 597,918,829 
14 526,632,062 
11 1 411,976,522 
9.1 i 342,491,707 
8 'J aft7 nns 1 1 1 


Hay 

Dairy products 
Wheat .... 








Poultry .... 
Other products 


[a) 


5 3 
12.6 


200,000,000 
472,492,249 


Grand total 




100 


$1,671,544,323 


100 $3,624,498,642 

i 


100 


$3,7.58,519,483 



a "Other products" include barley, buckwheat, flax fiber, flaxseed, hemp, 
hops, Irish potatoes, leaf tobacco, maple sirup, maple sugar, oats, rice, rye, 
sorghum molasses, sweet potatoes, and wool. 

But it is not so much in the amount of dairy 
product manufactured as in the way the business is 
done that the dairy industry shows its most remarka- 
ble advances. Up to 1850 the whole dairy output 
was produced, manufactured, and marketed from in- 
dividual farms. Since then the introduction and 
wonderful growth of associated dairying, or the fac- 
tory system, has taken place, and this period has 
also witnessed the introduction of so many and so 
varied machines and utensils that the dairy practice 
of forty or even twenty j^ears ago is entirely rev- 
olutionized in the methods of to-day. But while 
associated dairying has made rapid strides, both in 
butter and cheese making, it is only in cheese 
making that the factory system can be , said to have 
at all supplanted private dairying. In 1890 only 
a little more than 7 per cent of all the cheese 
produced was made outside of factories; while in the 



224 Milk and Its Prochicts. 

same year, of the 1,205,508,384 pounds of butter 
made in the country, only 181,284,916 pounds, or 
about 15 per cent, was made in factories. 

Develojyment of the factory system. — Associated 
dairj'ing, or the manufacture of the milk of several 
patrons at one place, under the eye of a single 
person, was at first limited wholly to cheese making. 
The system niaj^ be said to have been inaugurated 
by Jesse Williams, in Oneida county, N. Y., when 
in 1851 he began the manufacture of milk, produced 
by himself and several sons located on farms near 
by, into cheese under his immediate supervision. 
From this beginning the number of cheese factories 
increased, slowly at first but afterward more rapidlj', 
until in 1870 there were in operation 1,313 cheese 
factories. Up to this time butter factories were un- 
known, but within a few years began to be rapidly 
established, and in 1890 there were of both butter 
and cheese factories 4,712. Ten states — New York, 
Wisconsin, Iowa, Ohio, Pennsylvania, Illinois, Ver- 
mont, Minnesota, Michigan and Kansas, in the order 
named — contained nearly 90 per cent of all the fac- 
tories. Of these there were in New York 1,337, 
in Wisconsin 966, and in Iowa 500, or nearly 60 
per cent of the whole. 

When the first butter factories or creameries, as 
they are more generally called, wei'e established, the 
milk of the several patrons was drawn to the fac- 
tory, set in deep cans, usually surrounded by running 
water, and afterward skimmed and churned. After 
a time the gathered -cream system was introduced. 



Butter and Cheese Factories. 225 

Under this system the cream was raised upon the farm, 
usualh' by a cold deep -setting process, and the repre- 
sentative of the creamery, visiting the different farms, 
skimmed the cream, and left the skimmed milk upon 
the farm. Later on, during the decade beginning in 
1880, the centrifugal separator was introduced, and at 
the present time by far the larger number of but- 
ter factories are operated upon this system. As be- 
tween the factory system or the private dairy in the 
manufacture of dairy products, both have their ad- 
vantages and disadvantages. The advantages of the 
factory system are so great that practicallj' all of the 
cheese is made in this way, the small amount made 
upon farms and in private dairies being almost 
wholly made for domestic or strictly local consumi)- 
tion. Those advantages in the main are the saving 
of labor and the greater uniformity of product. It 
requires no more time and but slightly more labor 
to make six thousand pounds of milk into cheese 
than six hundred. Few private dairies produce more 
than the latter amount, so that the combination of 
ten men in a factory will result in saving the labor 
of at least five men in the manufacture of the pro- 
duct. Then the cost of building the proper curing 
room is much less under the factory sj'stem than in 
the private dairy. Conditions of temperature and 
moisture can readily be secured for a large amount 
of cheese cured together, that would practically be im- 
possible if the same amount of cheese was distrib- 
uted in ten or a dozen parcels and cured separately. 
In associated butter making, while the same ad- 



226 Milk and Its Products. 

vantages hold true as in cheese making, they do not 
manifest themselves to the same degree. There is un- 
doubtedly a considerable saving of labor and a vastly 
more uniform product where the milk of many patrons 
is manufactured into butter in a well equipped 
creamery under skilful supervision, but it is scarcely 
possible for a creamery handling the milk of many 
cows, scattered over a wide area and under the care 
of many persons, to make butter of so uniformly fine 
quality as is possible where not onlj- the milk, from 
the time it is drawn until the finished product is 
sent to market, but the care and food of the cows 
as well, are under the same skilful supervision. 
One of the chief advantages of both the cheese and 
butter factory system is that it removes from the 
farm, and particularly' from the farm home, a large 
amount of drudgery that in far too many cases fell 
upon those least able to bear it, the women of the 
household ; so that while the butter of the very high- 
est quality will probably for many jears to come be 
made in relatively small individual or private dairies 
upon farms, still the factory system is increasing 
very rapidly, and will continue to do so until pro- 
portionately as much butter as cheese is made in 
factories. 

Condensed mill-.— in 1856 a patent was granted 
to Gail Borden, Jr., on a process for "concentrating 
sweet milk by evaporation in vacuo, having no sugar 
or other foreign matter mixed with it." From small 
beginnings the business has grown to enormous pro- 
portions, and is still largely in the hands of the 



Dairy Legislation. 227 

descendants of the original patentee. At the present 
time the condensed product is made both with 
or without the addition of sugar, and is sold in 
bulk or in hermetieallj^ sealed cans, in which latter 
form it may be preserved for r.n indefinite time. 
By far the larger portion of the product is made 
with the addition of sugar, and is put up in cans. 

According to Dr. Babcock, in the plain condensed 
milk the water is reduced to about 59 per cent, the 
other constituents being increased in proportion, while 
the sugared product contains about 25 per cent of 
water and 36 per cent of cane sugar. 

The successful condensation of milk requires that 
the milk be produced under the best hygienic condi- 
tions and from the purest and most wholesome foods. 
Consequently we find among the patrons of condens- 
ing factories a highly developed state of dairy hus- 
bandrj^ 

Dairy legislation. — Dairy legislation in the United 
States has had two main objects. First, to secure 
to consumers of milk an unadulterated product. This 
has resulted in the establishment in many states of 
arbitrary legal standards for the quality of milk, and 
in others the passage of general laws prohibiting the 
adulteration of milk in any way ( See appendix C ) . 
Still, more than half the states have no laws what- 
ever in regard to the sale of milk, though most of 
the large cities in these states have adopted municipal 
regulations of the same general nature as the state 
laws. 

The second object of dairy legislation has been to 
p 



228 Milk and Its Products. 

guarantee the quality of a dairy product or to pre- 
vent the sale of a spurious product for a genuine one. 
The introduction of the manufacture of artificial but- 
ter or oleomargarine has led to both national and state 
regulation. The manufacture of oleomargarine, and 
particularly its sale as genuine butter, caused a great 
injury to the manufacturers of the genuine product, 
both in the sale of their goods and the prices re- 
ceived for the same. The state of New York was 
one of the first, if not the very first, to enact regu- 
lations controlling the sale of the imitation product, 
and in 1884 passed a law prohibiting the manufac- 
ture and sale of imitation butter within the limits of 
the state. This law^ w^as the subject of much litiga- 
tion, but has been upheld by the state and national 
courts. It has been pretty thoroughl}' enforced, and 
is still in operation. In 1886 the National Govern- 
ment passed a law imposing au income tax of two 
cents per pound upon all imitation butter made in 
the country, and levying special license taxes upon 
those engaged in its manufacture and sale. This has 
resulted in a measurable control of the product, and 
with the supplemental laws that have been passed in 
a large number of the states the matter is now under 
careful and strict regulation. These laws have not 
resulted, as was fondly hoped by many dairymen, in 
absolutely stopping the manufacture of imitation but- 
ter, but have resulted in a great improvement in the 
quality of the imitation goods and in securing inno- 
cent purchasers against fraud in palming off upon 
them a spurious for a genuine article. At the same 



Markets. 229 

time, the cheaper imitation butter has crowded out of 
the market the poorer grades of genuine butter, and 
so improved the general average quality' of genuine 
butter. 

More recently the manufacture of so-called filled 
cheese has been regulated in the same way, by the 
passage by the National Congress, in 1896, of a 
law similar to the oleomargarine act, placing a rev- 
enue tax upon all filled cheese manufactured, and a 
license tax upon the manufacturers and dealers. 
This filled cheese is made from skimmed milk, to 
which has been added a certain amount of neutral 
animal fat. 

Within the past twenty years the practice of mak- 
ing cheese from skimmed or partially skimmed milk 
has spread widelj^ throughout the United States. The 
result has been that the reputation of American cheese 
has greatly fallen in the market, both abroad and at 
home. A remedy has been sought by the passage in 
several states, notably New York and Wisconsin, of 
laws authorizing the use, on cheese made from whole 
milk, of "State Brands" guaranteeing the quality of 
cheese so branded. While cheese -makers were at 
first not inclined to' take advantage of these laws, 
the " State Brands ' ' are now extensivelj^ used with 
verj' gratifying results as to the reputation of cheese 
so branded in the general markets. 

Dairy markets. — In no one particular has the dairy 
industry developed in recent years more than in the 
line of production throughout the year. Formerlj' 
almost the whole product was made during the warm 



230 MilJc and Its Products. 

months. This is measurably so still in the case of 
cheese, but the demand has been constantly increas- 
ing for fresh butter the year round, and at the pres- 
ent time a fairly large proportion of the whole output 
is made during the winter months, the fresh butter 
commanding anywhere from two to ten cents per 
pound more than equally good butter that has been 
held in storage for several months. Very recently, 
with improvements in the methods of refrigeration 
and cold storage, the price of stored butter of the 
highest quality is reaching nearer to that of the 
fresh made goods, but the best consumers still con- 
tinue to call for a fresh article. 



APPENDIX. 

A. USEFUL RULES AND TESTS. 

Comparison of Thermometer Scales. 

Centigrade Scale — Freezing point of water = 
Boiling point of water = 100 

Difference 100 degrees. 
Fahrenheit Scale — Freezing point of water = 32 
Boiling point of water = 212 

Difference 180 degrees. 

100 degrees C. = 180 degrees F. 
5- " = 9 " 



To Change Degrees Centigrade to Equivalent Degrees 
Fahrenheit. 

Multiply by 9-5 and add 32 ; e. g. : 65° C. X 9-5 = 117 -f 32 
149° F. 



To Change Degrees Fahrenheit to Equivalent Degrees 
Centigrade. 

Subtract 32 and multiply by 5-9 ; e. g.: 98° F. — 32 = 66 X 5-9 
= 37°— C. 

To Find the Specific Gravity by the " Board of Health " 

Lactometer. 

Multiply the reading by .29 and add 1.000 ; e. g.: Observed reading, 
94 X -29 = 27.26 + 1.000 = 1.027.-|- specific gravity. 



(231) 



232 Milk and Its Products. 

To Change "Board of Health" Lactometer Degrees to 
Equivalent Quevenne Degrees. 

Multiply the "Board of Health" reading by .29; e. g.: "Board 
of Health" reading, 105 X -29 = 30.45 = 30-)- Quevenne reading. 

To Change Quevenne Lactometer Degrees to Equivalent 
"Board of Health" Degrees. 

Divide the observed Quevenne reading by .29; e. g.; Quevenne 
reading, 34 -^ .29 = 117. -j- ordinary or "Board of Health" reading. 

Temperature Correction for Lactometer. 

For Quevenne lactometer, .1 lactometer degree for each degree of 
temperature F. 

For ordinary or "Board of Health" lactometer, 1 lactometer degree 
for each 3 degrees of temperature F. 

To be added if the temperature is too high, or subtracted if it is 
too low. 

To be used only when the temperature variation is less than 10 
degrees from the standard of the lactometer. 

To Estimate Solids Not Fat, and Total Solids, from the 
Specific Gravity and Per Cent of Fat. 

The following formulae may be used : 

Babcock (1) S = IlJuU 
^ ' 3.8 

Babcock (2) S = _ii + .2 f 

^ ' 4 

Richmond (3) T = Ji -f- ^ - + .14 
4 5 

In the above L = corrected Quevenne lactometer reading,, f = per 
cent of fat, S = solids not f at ; T = total solids ; solids not fat -j- 
fat = total solids. 

To apply the above formulae, if the percentage of fat is 4.2 and 
the lactometer reading at 60° F. is 32, then 

(1) S = ^+-Ti , S = 32 + .7 (4.2) 
' 3.8 3.8 

.7 of 4.2 = 2.94 -f 32 = 34.94 h- 3.8 = 9.19 = solids not fat. 
9.19 -|- 4.2 = 13,39 = total solids, 



Useful Bides and Tests. 233 

(2) S = -11 + .2 f, S = -^ + .2 (4.2) 

4 4 

32 -^ 4 = 8, .2 (4.2) = .84, 8 + .84 = 8.84 = solids not fat. 
8.84 4- 4.2 = 13.04 = total solids. 

(3) T = ^ -f ^ + .14, T = -^ + tA^ + .14 

4 5 4 5 

32 ^ 4 = 8, 6 X 4.2 = 25.2 ^ 5 = 5.04. 
8 -f 5.04 -f .14 = 13.18 = total solids. 

Litmus Test. 
A method of determining whether a liquid is acid or alkaline. 
In acid solutions, blue litmus turns red. 
In alkaline solutions, red litmus turns blue. 

Phenolphthalein Test. 

A method of determining whether a liquid is acid or alkaline. 

In acid solutions, if phenolphthalein is added no change in color 
is produced. 

In alkaline solutions, if phenolphthalein is added the liquid turns 
pink. 

To Determine the Percentage op Lactic Acid in Milk by the 
Use of Decinormal Alkali, or Farrington's Alkaline Tablets. 

Each c. c. decinormal alkali neutralizes .009 grams lactic acid. 
Therefore, multiply the number of c. c. decinormal alkali used by 
009 and divide the product by the number of grams of milk taken. 
(Grams = c. c. X 1.032); e. g.: 20 c. c. of milk require 9 c. c. deci- 
normal alkali to neutralize the acid. The per cent of acid is — 

.009 X 9 = .081 grams lactic acid. 

.081 -- 20.64 = .0039, or .39 %. 

Each alkaline tablet = 3.8 c. c. decinormal alkali. Each tablet 
is dissolved in 10 c. c. water. Each c. c. tablet solution = .38 
c. c. decinormal alkali. Therefore, each c. c. tablet solution will 
neutralize .009 X .38 = .0034 grams lactic acid. Therefore, mul- 
tiply the number of c. c. of tablet solution used by .0034 and 
divide by the number of grams of milk taken (grams = c. c. X 
1.032); e. g.: 

20 c. c. of cream require 35 c. c. of tablet solution to neutralize 
the acid. The per cent of acid is — 

.0034 X 35 = .119 grams lactic acid. 
■ 419 ^ 20.64 = .0058, or .58%. 



234 Milk and Its Products. 

To Select Milk for Pasteurization. 

Dissolve any convenient number of Farrington alkaline tablets in 
an equal number of ounces of water. Provide any convenient small 
measure, and to one measure of milk add two measures of the pre- 
pared tablet solution. If the milk remains uncolored, it contains 
more than .2 of 1 per cent of acid, and is too sour to be safely 
used. If it is colored pink, it contains less than .2 of 1 per cent 
of acid, and may safely be used for pasteurizing or sterilizing. 
Or, the tablet solution will be of very nearly the same strength, 
and may be used in the same way, if 3 tablets are dissolved in 90 
c. c. of water. 

To Prepare Artificial " Starter " or Ferment for Ripening 
Milk or Cream. 

Sterilize ten pounds of fresh, sweet skimmed or whole milk at 
180° F. Cool to 90° F., and add sufi&cient dry lactic ferment to 
secure coagulation in twenty-four hours. When coagulated, add this 
to the extent of 10 per cent to enough sterilized whole or skimmed 
milk to make sufficient " starter " for one day's use. Reserve each 
day enough of this starter to prepare the starter for the next day, 
and use the remainder for ripening the milk or cream, using for 
this from 2 to 5 per cent, according to circumstances. Keep the 
starter as nearly as possible at a uniform temperature of 80° F. 

Monrad Rennet Test. 

To determine the ripeness of milk for cheese making, put 5 c. c. 
commercial rennet in a 50 c. c. flask and fill with water to the 
mark. Put 200 c. c. of milk at 86° F. in a suitable tin cup, and 
allow it to float in the vat. Add 5 c. c. of the diluted rennet, and 
note carefully the time required for the first appearance of coagu- 
lation. The time required will depend upon the amount of milk 
and rennet used, the strength of the rennet, the temperature and 
the ripeness of the milk. All except the last remaining constant 
from day to day, the degree of ripeness is measured by the time 
required for coagulation. The riper the milk the shorter the time; 
ordinarily from one and one-half to two minutes will be required. 
The diluted rennet must be made fresh every day. 

Marschall Rennet Test. 

To determine the ripeness of milk for cheese making, fill the 
vessel to the o mai'k with milk, add a pipette full of commercial 



Useful Rides and Tests. 235 

rennet, stir quickly, and place in such a position that tlie milk may 
flow freely from the orifice. When the milk ceases to flow, note the 
number of graduations exposed. The riper the milk the less the 
number of exposed graduations. 

Hot Iron Test. 

A test used to indicate the maturity of curd in cheese making. 
The maturity is usually coincident with the amount of lactic acid 
present, so that the test is commonly called the hot iron test for 
acid. 

The test is made by heating a bar of iron just short of redness, 
or so that it will hiss readily. A mass of curd is squeezed in the 
hand till all the whey possible is pressed out. The curd is then 
applied to the iron ; the surface of the curd, melted by the heat, 
sticks to the iron, and the remainder is carefully and gently pulled 
away. If the curd is very immature, the melted part readily sep- 
arates from that not affected by the heat, but when more mature, 
numerous fine thi*eads of casein ai'e drawn out when the two parts 
are separated, the length of these thi-eads depending upon the ma- 
turity of the curd, and commonly measured in terms of acid, thus, 
3^-inch acid, 2-inch acid, etc. 

To Calibrate or Test the Accuracy of Graduation op 
Glassware Used in the Babcock Test. 

Observe that the graduations are at equal distances apart. Fill 
the bottle carefully to the o point with clean rain water, wipe out 
the neck carefullj'', and add from a pipette or burette 2 c. c. water. 
It should fill the bottle exactly to the 10 point. Or, weigh the 
bottle filled with clean rain water to the o point with delicate bal- 
ances, fill to the 10 point and weigh again. The difference in weight 
should be 2 grams. Or, into a dry, empty bottle put 2 c. c. or 
27.18 grams mercury, insert a tight-fitting plug carefully to the 10 
point, and invert the bottle ; the mercury should just reach to the 
o point. The pipette should hold 17. G grams of water, or 239 
grams of mei'cury. Any piece showing a discrepancy of 2 per cent 
should be discarded. 

To Test Butter or Cheese With the Babcock Test. 

Weigh out on a balance sensitive to .1 gram, from 4 to 8 grams 
of the substance to be tested. Divide into small pieces and put 
into an ordinary test bottle,' or bottle with detachable neck, with 



236 Blilk mid Its Prochicts. 

about 10 c. c. of warm water. Add the acid, and complete the test 
in the ordinary way. The percentage of fat will be found by the 
following proportion : 

Weight of sample : 18 : : observed reading : per cent of fat ; or 

18 X observed reading _ ^^^ ^^^^ ^^ ^^^. 
weight of sample 
e. g. : 4.8 grams of cheese tested, showed a reading of 9.2 per cent 
fat in the test bottle. The cheese contained : 

^^ ^ ^-^ = 34. .5 per cent fat. 
4.8 



Metric System. 



237 



B. METRIC SYSTEM. 

The meter is the primary unit of length. It is equal to 
TTTiyoV^oot^i part of the distance measured on a meridian of 
the earth from the equator to the pole, and equals about 39.37 
inches. 





Measures of Length. 




Equivalents. 


Myriameter 




10,000 


meters 


6.2137 miles 


Kilometer 




1,000 


" 


j 0.62137 mile, or 
i 3280 ft. 10 in. 


Hectometer 




100 


i( 


328 ft. 1 in. 


Dekameter 




10 


i( 


393.7 in. 


Meter 




1 


meter 


39.37 in. 


Decimeter 




.1 


i( 


3.937 in. 


Centimeter 




.01 


u 


.3937 in. 


Millimeter 




.001 


<( 


.03937 in. 



Hectare 

Are 

Centare 



Measures of Surface. 



10,000 sq. meters 
100 " 
1 " meter 



Equivalents. 



2.471 acres 

119.6 sq. yards 

1550. sq. inches. 



Measures of Capacity. 


Equivalents. 




No. OF 
Liters. 


Cubic Measure. 


Dry Measure. 


Liquiii or AVine 
Measure. 


Kiloliter, or Stere 

Hectoliter 

Dekaliter 

Liter 

Deciliter 

Centiliter 

Milliliter 


1000 

100 

10 

1 
.1 

.01 
.001 


1 cu. meter 

.1" 
10 cu. decimeters 
1 cu. decimeter 

.1" 
10 cu. centimeters 
.leu. centimeter 


1.308 cu. yards 

2 bu. 3.35 pks. 

9.08 quarts 
.909 quart 

6.1022 cu. inches 
.6102 cu. inch 
.001 " " 


264.17 gal. 
26.417 gal. 
2.6417 gal. 
1.0567 qts. 
.845 gill 
.338 fl. oz. 
.27 fl. dram 



238 



Milk and Its Products. 



System of Weights. 


Equivalents. 




No. OF Geamb. 


Weight of Water 


Avoirdupois 




Maximum Density. 


Weight. 


Millier, or Tonneau 


1,000,000 


1 cu. meter 


2204.6 pounds 


Quintal 


100,000 


1 hectoliter 


220.46 


Myriagram 


10,000 


1 dekaliter 


22.046 " 


Kilogram, or Kilo 


1,000 


1 Uter 


2.2046 ♦' 


Hectogram 


100 


1 deciliter 


3.5274 oz. 


Dekagram 


10 


10 cu. centimeters 


.3527 " 


Gram 


1 


1 cu. centimeter 


15.432 grains 


Decigram 


.1 


■t (( «( 


1.5432 " 


Centigram 


.01 


10 cu. millimeters 


.1543 grain 


Milligram 


.001 


1 " millimeter 


.0154 " 



Common 
Measure. 


Equivalents. 


Common 

Measure. 


Equivalents. 


An inch 


2.54 centimeters 


A cu. yard 


.7646 cu. meter 


Afoot 


.3048 meter 


A cord 


3.624 steres 


A yard 


.9144 " 


A liquid qt. 


.9465 liter 


A rod 


5.029 meters 


A gallon 


3.786 liters 


A mile 


1.6093 kilometers 


A dry qt. 


1.101 " 


A sq. inch 


6.462 sq. centimeters 


A peck 


8.811 " 


A " foot 


.0929 sq. meter 


A bushel 


35.24 " 


A " yard 


.8361 " 


An oz. avoirdupois 


28.35 grams 


A " rod 


25.29 sq. meters 


A pound " 


.4536 kilogram 


An acre 


.4047 hectare 


A ton 


.9072 tonneau 


A sq. mile 


259 hectares. 


A grain troy 


.0648 gram 


A cu. inch 


16.39 cu. centimeters 


An oz. " 


31.104 grams 


A " foot 


.02S32 cu. meter 


A pound " 


.3732 kilogram 



standards for Milk — Dairy Laws. 239 

C. LEGAL STANDARDS FOB MILK— DAIRY LAWS. 

The following states and territories ; viz., Alabama, Arizona, 
Arkansas, California, Colorado, Connecticut, Delaware, Florida, Idaho, 
Illinois, Kansas, Kentucky, Louisiana, Maryland, Mississippi, Mis- 
souri, Montana, Nebraska, Nevada, New Mexico, North Carolina, 
North Dakota, Oklahoma, South Dakota, Tennessee, Texas, Virginia, 
West Virginia and Wyoming, have established no legal standard. 

The Dominion of Canada, Indiana and Utah have general laws 
prohibiting dilution or skimming. 

In the other states the percentage standards are as follows : 

Specific Total 

gravity, solids, ^. Fats, i. 

District of Columbia 12 3 

Georgia 12 3.5 

Iowa 8 

Maine 12 3 

Massachusetts (Apr. to Aug., inclusive) 12 3 

(Sept. to Mar., inclusive) .... 13 3.7 

Michigan 1.029-1.033 12.5 3 

Minnesota 13 3.5 

New Hampshire 13 

New Jersey 12 

New York 12 3 

Ohio (May and June) 11.5 2.88 

(July to April, inclusive) 12 3 

Oregon 12 3 

Pennsylvania* 1.029-1.033 12.5 3 

Rhode Island 12 2.5 

South Carolina 11.5 3 

Vermont (May and June) 12 

(July to April, inclusive) 12.5 3.25 

Washington • • 3 

Wisconsin • • 3 

The full texts of the national oleomargarine and filled cheese laws 
are as follows : 



* Applies only to cities of the second class. 



240 Milk and Its Products. 

THE OLEOMARGARINE LAW. 

AN ACT defining butter, also imposing a tax \ipon and regulating the manu- 
facture, sale, importation and exportation of oleomargarine. 

Be it enacted by the Senate and House of Representatives of the 
United States of America in Congress assembled, That for the pur- 
pose of this act the word "butter" shall be understood to mean 
the food product usually known as butter, and which is made exclu- 
sively from milk or cream, or both, with or without common salt, 
and with or without additional coloring matter. 

Section 2. That for the purposes of this act certain manufac- 
tured substances, certain exti'acts, and certain mixtures and com- 
pounds, including such mixtures and compounds with butter, shall 
be known and designated as " oleomargarine ; " namely : All sub- 
stances heretofore known as oleomargarine, oleo, oleomargarine oil, 
butterine, lardine, suine and neutral ; all mixtures and compounds 
of oleomargarine, oleo, oleomargarine-oil, butterine, lardine, suine, 
and neutral ; all lard extracts and tallow extracts ; and all mix- 
tures and compounds of tallow, beef -fat, suet, lard, lard-oil, veg- 
etable-oil, annatto and other coloring matter, intestinal fat, and offal 
fat made in imitation or semblance of butter, or when so made 
calculated or intended to be sold as butter, or for butter. 

Skc. 3. That special taxes are imposed as follows : 

Manufacturers of oleomargarine shall pay six hundred dollars. 
Every person who manufactures oleomargarine for sale shall be 
deemed a manufacturer of oleomargarine. 

Wholesale dealers in oleomargarine shall pay four hundred and 
eighty dollars. Eveiy person who sells or offers for sale oleomar- 
garine in the original manufacturer's packages shall be deemed a 
wholesale dealer in oleomargarine. But any manufacturer of oleo- 
margarine who has given the required bond and paid the required 
special tax, and who sells only oleomargarine of his own produc- 
tion, at the place of manufacture, in the original packages to which 
the tax-paid stamps are afl&xed, shall not be required to pay the 
special tax of a wholesale dealer in oleomargarine on account of 
such sales. 

Retail dealers in oleomargarine shall pay forty-eight dollars. 
Every person who sells oleomargarine in less quantities than ten 
pounds at one time shall be regarded as a retail dealer in oleo- 
margarine. And sections thirty-two hundred and thii*ty-two, thirty- 
two hundred and thirty-three, thirty-two hundred and thirty-four. 



Dairy Laws. 241 

thirty-two hundred and thirty-five, thirty-two hundred and thirty- 
six, thirty-two hundred and thirty-seven, thirty-two hundx-ed and 
thirty-eight, thirty-two hundred and thirty-nine, thirty-two hundred 
and forty, thirty-two hundred and forty-one, and thirty-two hundred 
and forty-three of the Revised Statutes of the United States are, so 
far as applicable, made to extend to and include and apply to the 
special taxes imposed by this section, and to the persons upon 
whom they are imposed. 

Sec. 4. That every person who carries on the business of a 
manufacturer of oleomargarine without having paid the special tax 
therefore, as required by law, shall, besides being liable to the 
payment of the tax, be fined not less than one thousand and not 
more than five thousand dollars ; and every person who carries on 
the business of a wholesale dealer in oleomargarine without having 
paid the special tax therefor, as required by law, shall, besides 
being liable to the payment of the tax, be fined not less than five 
hundred nor more than two thousand dollars ; and every person 
who carries on the business of a retail dealer in oleomargarine 
without having paid the special tax therefor, as required by law, 
shall, besides being liable to the payment of the tax, be fined not 
less than fifty nor more than five hundred dollars for each and 
every offense. 

Sec. 5, That every manufacturer of oleomargarine shall file with 
the collector of internal revenue of the district in which his man- 
ufactory is located such notices, inventories and bonds, shall keep 
such books and render such returns of material and products, 
shall put up such signs and affix such number to his factory, 
and conduct his business under such surveillance of officers and 
agents, as the Commissioner of Internal Revenue, with the appro- 
val of the Secretary of the Treasury, may, by regulation, require. 
But the bond required of such manufacturer shall be w^ith sureties 
satisfactory to the collector of internal revenue, and in a penal 
sum of not less than five thousand dollars ; and the sum of said 
bond may be increased from time to time and additional sureties re- 
quired at the discretion of the collector, or under instructions of 
the Commissioner of Internal Revenue. 

Sec. 6. That all oleomargarine shall be packed by the manu- 
facturer thereof in firkins, tubs or other wooden packages, not be- 
fore used for that purpose, each containing not less than ten 
pounds, and marked, stamped and branded as the Commissioner of 
Internal Revenue, with the approval of the Secretary of the Treas- 



242 Milk and Its Products. 

ury, shall prescribe ; and all sales made by manufacturers of oleo- 
raargarine and wholesale dealers in oleomargarine shall be in 
original stamped packages. Retail dealers in oleomargarine must 
sell only from original stamped packages, in quantities not 
exceeding ten pounds, and shall pack the oleomargarine sold by 
them in suitable wooden or paper packages, which shall be marked 
and branded as the Commissioner of Internal Revenue, with the 
approval of the Secretary of the Treasury, shall prescribe. Every 
person who knowingly sells or offers for sale, or delivers or offers 
to deliver, any oleomargarine in any other form than in new wooden 
or paper packages as above described, or who packs in any pack- 
age any oleomargarine in any manner contrary to law, or who 
falsely brands any package or afi&xes a stamp on any package 
denoting a less amount of tax than that required by law, shall 
be fined for each offense not more than one thousand dollars and 
be imprisoned not more than two years. 

Sec. 7. That every manufacturer of oleomargarine shall securely 
affix, by pasting on each package containing oleomargarine manufac- 
tured by him, a label on which shall be printed, besides the number 
of the manufactory, and the district and state in wliich it is situ- 
ated, these words "Notice. — The manufacturer of the oleomargarine 
herein contained has complied with all the requirements of law. 
Every person is cautioned not to use either this package again or 
the stamp thereon again, nor to remove the contents of this pack- 
age without destroying said stamp, under the penalty provided by 
law in such cases." Every manufacturer of oleomargarine who 
neglects to affix such label to any package containing oleomarga- 
rine made by him, or sold or offered for sale by or for him, and 
every person who removes any such label so affixed from any such 
package, shall be fined fifty dollars for each package in respect to 
which such offense is committed. 

Sec. 8. That upon oleomargarine which shall be manufactured 
and sold, or removed for consumption or use, there shall be assessed 
and collected a tax of two cents per pound, to be paid by the 
manufacturer thereof ; and any fractional part of a pound in a 
package shall be taxed as a pound. The tax levied by this sec- 
tion shall be represented by coupon stamps ; and the provisions of 
existing laws governing the engraving, issue, sale, accountability, 
effacement, and destruction of stamps relating to tobacco and snuff, 
as far as applicable, are hereby made to apply to stamps provided 
for by this section. 



Dairy Laws. 243 

Sec. 9. That whenever any manufacturer of oleomargarine sells, 
or removes for sale or consumption, any oleomargarine upon which 
the tax is required to l)e paid by stamps, without the use of the 
in-oper stamps, it shall be the duty of the Commissioner of Internal 
Revenue, within a period of not more than two years after such 
sale or removal, upon satisfactory proof, to estimate the amount 
of tax which has been omitted to be paid, and to make an assess- 
ment therefor and certify the same to the collector. The tax so 
assessed shall be in addition to the penalties imposed by law for 
such sale or removal. 

Sec. 10. That all oleomargarine imported from foreign countries 
shall, in addition to any import duty imposed on the same, pay an 
internal revenue tax of fifteen cents per pound, such tax to be 
represented by coupon stamps as in the case of oleomargarine 
manufactured in the United States. The stamps shall be affixed 
and canceled by the owner or importer of the oleomargarine while 
it is in the custody of the proper custom-house ofi&cers ; and the 
oleomargarine shall not pass out of the custody of said officers 
until the stamps have been so> affixed and canceled, but shall be put 
up in wooden packages, each containing not less than ten pounds, 
as prescribed in this act for oleomargarine manufactured in the 
United States, before the stamps are affixed ; and the owner or 
importer of such oleomargarine shall be liable to all the penal 
provisions of this act prescribed for manufacturers of oleomargarine 
manufactured in the United States. Whenever it is necessary to 
take any oleomargarine so imported to any place other than the 
public stores of the United States for the purpose of affixing and can- 
celinjj such stamps, the collector of customs of the port where such 
oleomargarine is entered shall designate a bonded warehouse to which 
it shall be taken, under the control of such customs officer as such 
collector may direct ; and every officer of customs who permits 
any such oleomargarine to pass out of his custody or control with- 
out compliance by the owner or importer thereof with the provi- 
sions of this section relating thereto, shall be guilty of a misde- 
meanor, and shall be fined not less than one thousand dollars nor 
more than five thousand dollars, and imprisoned not less than six 
months nor more than three years. Every person who sells or 
offers for sale any imported oleomargarine, or oleomargarine pur- 
porting or claimed to have been imported, not put up in pack- 
ages and stamped as provided by this act, shall be fined not less 
than five hundred dollars nor more than five thousand dollars, 

Q 



244 Milk and Its Products. 

and be imprisoned not less than six months nor more than two 
years. 

Sec. 11. That every person who knowingly purchases or receives 
for sale any oleomargarine which has not been branded or stamped 
according to law shall be liable to a penalty of fifty dollars for 
each such offense. 

Sec. 12. That every person who knowingly purchases or receives 
for sale any oleomargarine from any manufacturer who has not 
paid the special tax shall be liable for each offense to a penalty 
of one hundred dollars, and to a forfeiture of all articles so pur- 
chased or received, or of the full value thereof. 

Sec. 13. That whenever any stamped package containing oleomar- 
garine is emptied, it shall be the duty of the person in whose hands 
the same is, to destroy utterly the stamps thereon ; and any per- 
son who willfully neglects or refuses so to do shall for each such 
offense be fined not exceeding fifty dollars, and imprisoned not less 
than ten days nor more than six months. And any person who 
fraudulently gives away or accepts from another, or who sells, buys, 
or uses for packing oleomargarine, any such stamped package, shall 
for each such offense be fined not exceeding one hundred dollars, 
and be imprisoned not more than one year. Any revenue ofiicer 
may destroy any emptied oleomargarine package upon which the tax- 
paid stamp is found. 

Sec. 14. That there shall be in the ofl&ce of the Commissioner 
of Internal Revenue an analytical chemist and a microscopist, who 
shall each be appointed by the Secretary of the Treasury, and shall 
each receive a salary of two thousand five hundred dollars pfr an- 
num ; and the Commissioner of Internal Revenue may, whenever in 
his judgment the necessities of the service so require, employ chem- 
ists and microscopists, to be paid such compensation as he may 
deem proper, not exceeding in the aggregate any appropriation made 
for that purpose. And such Commissioner is authorized to decide 
what substances, extracts, mixtures or compounds which may be sub- 
mitted for his inspection in contested cases are to be taxed under 
this act ; and his decision in matters of taxation under this act 
shall be final. The Commissioner may also decide whether any 
substance made in imitation or semblance of butter, and intended 
for human consumption, contains ingredients deleterious to the pub- 
lic health ; but in case of doubt or contest his decisions in this 
class of cases may be appealed from to a board hereby constituted 
for the purpose, and composed of the Surgeon-General of the Army, 



Dairy Laws. 245 

the Surgeon-General of the Navy, and the Secretary of Agricul- 
ture ; and the decisions of this board shall be final in the prem- 
ises. 

Sec. 15. That all packages of oleomargarine subject to tax under 
this act that shall be found without stamps or marks as herein pro- 
vided, and all oleomargarine intended for human consumption which 
contains ingredients adjudged, as hereinbefore provided, to be del- 
eterious to the public health, shall be forfeited to the United States. 
Any person who shall willfully remove or deface the stamps, marks, 
or brands on package containing oleomargarine taxed as provided 
herein shall be guilty of a misdemeanor, and shall be punished by 
a fine of not less than one hundred dollars nor more than two thou- 
sand dollars, and by imprisonment for not less than thirty days nor 
more than six months. 

Sec. 16. That oleomargarine may be removed from the place of 
manufacture for export to a foreign country without paj^ment of 
tax or affixing stamps thereto, under such regulations and the fil- 
ing of such bonds and other security as the Commissioner of In- 
ternal Revenue,- with the approval of the Secretary of the Treas- 
ury, may prescribe. Every person who shall export oleomargarine 
shall brand upon every tub, firkin, or other package containing such 
article the word " oleomargarine," in plain Roman letters not less 
than one-half inch square. 

Sec. 17. That whenever any person engaged in carrying on the 
business of manufacturing oleomargarine defrauds, or attempts to 
defraud, the United States of the tax on the oleomargarine pro- 
duced by him, or any part thereof, he shall forfeit the factory and 
manufacturing apparatus used by him, and all oleomargarine and 
all raw material for the production of oleomargarine found in the 
factory and on the factory premises, and shall be fined not less than 
five hundred dollars, nor more than five, thousand dollars, and be 
imprisoned not less than six months nor more than three years. 

Sec. 18. That if any manufacturer of oleomargarine, any dealer 
therein, or any importer or exporter thereof shall knowingly or 
willfully omit, neglect or refuse to do, or cause to be done, any of 
the things required by law in the carrying on or conducting of his 
business, or shall do anything by this act prohibited, if there be 
no specific penalty or punishment imposed by any other section of 
this act for the neglecting, omitting, or refusing to do, or for the 
doing or causing to be done, the thing required or prohibited, he 
shall pay a penalty of one thousand dollars ; and if the person so 



246 Milk and Its Products. 

offending be the manufacturer of or a M^iolesale dealer in oleomar- 
garine, all the oleomargarine owned by him, or in which he has 
any interest as owner, shall be forfeited to the United States. 

Sec. 19. That all fines, penalties, and forfeitures imposed by 
this act may be recovered in any court of competent jurisdiction. 

Seo. 20. That the Commissioner of Internal Revenue, with the 
approval of the Secretary of the Treasury, may make all needful reg- 
ulations for the carrying into effect of this act. 

Sec, 21. That this act shall go into effect on the ninetieth day 
after its passage ; and all wooden packages containing ten or more 
pounds of oleomargarine found on the premises of any dealer on 
or after the ninetieth day succeeding the date of the passage of 
this act shall be deemed to be taxable under section eight of this 
act, and shall be taxed, and shall have affixed thereto the stamps, 
marks, and brands required by this act or by regulations made 
pursuant to this act ; and for the purposes of securing the affixing 
of the stamps, marks, and brands required by this act, the oleomar- 
garine shall be regarded as having been manufactured and sold, or 
removed from the manufactory for consumption or use, on or after 
the day this act takes effect ; and such stock on hand at the time 
of the taking effect of this act may be stamped, marked, and 
branded under special regulations of the Commissioner of Internal 
Revenue, approved by the Secretary of the Treasury ; and the Com- 
missioner of Internal Revenue may authorize the holder of such 
packages to mark and brand the same and to affix thereto the pro- 
per tax-paid stamps. 

Approved August 2, 1886. 



THE FILLED CHEESE LAW. 

AN ACT defining cheese, and also imposing a tax upon and regulating the 
manufacture, sale, importation and exportation of "filled cheese." 

Be it enacted by the Senate and House of Representatives of the 
United States of America in Congress assembled, That for the pur- 
poses of this act, the word " cheese " shall be understood to mean 
the food product known as cheese, and which is made from milk 
or cream, and without the addition of butter, or any animal, vege- 
table, or other oils or fats foreign to such milk or cream, with or 
without additional coloring matter. 



Dairy Laws. 247 

Section 2. That for the purpo^ses of this act certain substances 
and compounds shall be known and designated as " filled cheese," 
namely: All substances made of milk or skimmed milk, with the 
admixture of butter, animal oils or fats, vegetable or any other oils, 
or compounds foreign to such milk, and made in imitation or sem- ) 
blance of cheese. 

Sec. 3. That special taxes are imposed as follows: 
Manufacturers of filled cheese shall pay four hundred dollars for 
each and every factory per annum. Every person, firm, or corpora- 
tion who manufactures filled cheese for sale shall be deemed a man- 
ufacturer of filled cheese. Wholesale dealers in filled cheese shall pay j;^ 
two hundred and fifty dollars per annum. Every person, firm, or cor- 
poration who sells, or offers for sale filled cheese in the original man- 
ufacturer's packages for resale, or to retail dealers as hereinafter de- 
fined, shall be deemed a wholesale dealer in filled cheese. But any 
manufacturer of filled cheese who has given the required bond and 
paid the required special tax, and who sells only filled cheese of his 
own production, at the place of manufacture, in the original pack- 
ages, to which the tax-paid stamps are afiixed, shall not be required 
to pay the special tax of a wholesale dealer in filled cheese on ac- 
count of such sales. 

Retail dealers in filled cheese shall pay twelve dollars per annum. 
Every person who sells filled cheese at retail, not for resale, and 
for actual consumption, shall be regarded as a retail dealer in filled 
cheese, and sections thirty-two hundred and thirty-two, thirty-two 
hundred and thirty-three, thirty-two hundred and thirty-four, thirty- 
two hundred and thirty-five, thirty-two hundred and thirty-six, thirty- 
two hundred and thirty-seven, thirty-two hundred and thirty-eight, 
thirty-two hundred and thirty-nine, thirty-two hundred and forty, thir- 
ty-two hundi-ed and forty-one, thirty-two hundred and forty-three of 
the Revised Statutes of the United States are, so far as applicable, 
made to extend to and include and apply to the special taxes im- 
posed by this section and to the persons, firms, or corporations upon 
whom they are imposed: Provided, That all special taxes under this 
act shall become due on the first day of July in every year, or on 
commencing any manufacture, trade, or business on which said tax 
is imposed. In the latter case the tax shall be reckoned propor- 
tionately from the first day of the month in which the liability to 
the special tax commences to the first day of July following. 

Sec. 4 That every person, firm or corporation who carries on the 
business of a manufacturer of filled cheese without having paid the 



248 Milk and Its Products. 

special tax therefor, as required by law, shall, besides being liable 
to ihe payment of the tax, be fined not less than four hundred dol- 
lars and not more than three thousand dollars; and every person, 
firm, or corporation who carries on the business of a wholesale dealer 
in filled cheese without having paid the special tax therefor, as re- 
quired by law, shall, besides being liable to the payment of the tax, 
be fined not less than two hundred and 'fifty dollars, nor more than 
one thousand dollars; and every person, firm, or corporation, who car- 
ries on the business of a retail dealer in filled cheese without having 
paid the special tax therefor, as required by law, shall, besides being 
liable for the payment of the tax, be fined not less than forty nor 
more than five hundred dollars for each and every offense. 

Sec. 5. That every manufacturer of filled cheese shall file with 
the collector of internal revenue of the district in which his man- 
ufactory is located, such notices, inventories, and bonds, shall keep 
such books and render such returns of materials and products, shall 
put up such signs and affix such number to his factory, and con- 
duct his business under such surveillance of officers and agents as 
the Commissioner of Internal Revenue, with the approval of the 
Secretary of the Treasury, may by regulation require. But the bond 
required of such manufacturer shall be with sureties satisfactory to 
the collector of internal revenue, and in a penal sum of not less than 
five thousand dollars; and the amount of said bond may be in- 
creased from time to time, and additional sureties required, at the 
discretion of the collector or under instructions of the Commissioner 
of Internal Revenue. Any manufacturer of filled cheese who fails 
to comply with the provisions of this section, or with the regula- 
tions herein authorized, shall be deemed guilty of a misdemeanor, 
and upon conviction thereof shall be fined not less than five hun- 
dred nor more than one thousand dollars. 

Sec. 6. That filled cheese shall be packed by the manufacturers 
in wooden packages only, not before used for that purpose, and 
marked, stamped, and branded with the words " filled cheese," in 
black-faced letters not less than two inches in length, in a circle 
in the center of the top and bottom of the cheese; and in black- 
faced letters of not less than two inches in length in line from 
the top to the bottom of the cheese, on the side in four places 
equidistant from each other ; and the package containing such cheese 
shall be marked in the same manner, and in the same number of 
places, and in the same descrij^tion of letters as above provided for 
the marking of the cheese; and all sales or consignments made by 



Dairy Laws. 249 

manufacturers of filled cheese to wholesale dealers in filled cheese 
or to exporters of filled cheese shall be in original stamped pack- 
ages. Retail dealers in filled cheese shall sell only from original 
stamped packages, and shall pack the filled cheese, when sold, in 
suitable wooden or paper packages which shall be marked and branded 
in accordance with the rules and regulations to be prescribed by the 
Commissioner of Internal Revenue, with the approval of the Secre- 
tary of the Treasury. Every person who knowingly sells or offers 
to sell, or delivers or offers to deliver, filled cheese in any other 
form than in new wooden or paper packages, marked and branded 
as hereinbefore provided and as above described, or who packs in any 
package or packages filled cheese in any manner contrary to law, 
or who falsely brands any package or aflflxes a stamp on any pack- 
age denoting a less amount of tax than that required by law, shall 
upon conviction thereof be fined for each and every offense not 
less than fifty dollars and not more than five hundred dollars, 
or be imprisoned not less than thirty days nor more than one 
year. 

Sec. 7. That all retail and wholesale dealers in filled cheese 
shall display in a conspicuous place in his or their salesroom a sign 
bearing the words, " Filled cheese sold here " in black-faced letters not j 
less than six inches in length, upon a white ground, with the name 
and number of the revenue district in which his or their business 
is conducted; and any wholesale or retail dealer in filled cheese 
who fails or neglects to comply with the provisions of this section 
shall be deemed guilty of a misdemeanor, and shall on conviction 
thereof be fined for each and every offense not less than fifty dol- 
lars and not more than two hundred dollars. 

Sec. 8. That every manufacturer of filled cheese shall securely 
affix, by pasting on each package containing filled cheese manufac- 
tured by him, a label on which shall be printed, besides the num- 
ber of the manufactory and the district and state in which it is 
situated, these words: « Notice.— The manufacturer of the filled cheese 
herein contained has complied with all the requirements of the 
law. Every person is cautioned not to use either this package 
again or the stamp thereon again, nor to remove the contents of 
this package without destroying said stamp, under the penalty pro- 
vided by law in such cases." Every manufacturer of filled cheese 
who neglects to affix such label to any package containing filled 
cheese made by him or sold or offered for sale by or for him, 
and every person who removes any such label so affixed from any 



250 Milk and Its Products. 

such package, shall be fined fifty dollars for each package in re- 
spect to which such offense is committed. 

Sec. 9. That upon all filled cheese which shall be manufactured 
there shall be assessed and collected a tax of one cent per pound, 
to be paid by the manufacturer thereof; and any fractional part of 
a pound in a package shall be taxed as a pound. The tax levied 
by this section shall be represented by coupon stamps; and the 
provisions of existing laws governing the engraving, issue, sale, 
accountability, effacement, and destruction of stamps relating to 
tobacco and snuff, as far as applicable, are hereby made to apply 
to stamps provided for by this section. 

Sec. 10. That whenever any manufacturer of filled cheeese sells 
or removes for sale or consumption any filled cheese upon which 
the tax is required to be paid by stamps, without paying such tax, 
it shall be the duty of the Commissioner of Internal Revenue, 
within a period of not more than two years after such sale or re- 
moval, upon satisfactory proof, to estimate the amount of tax which 
has been omitted to be paid and to make an assessment therefor 
and certify the same to the collector. The tax so assessed shall be 
in addition to. the penalties imposed by law for such sale or removal. 

Sec. 11. That all filled cheese, as herein defined, imported fi'om 
foreign countries shall, in addition to any import duty imposed on 
the same, pay an internal revenue tax of eight cents per pound, 
such tax to be represented by coupon stamps; and such imported 
filled cheese and the packages containing the same shall be stamped, 
marked, and branded, as in the case of filled cheese manufactured 
in the United States. 

Sec. 12. That any person who knowingly purchases or receives 
for sale any filled cheese which has not been branded or stamped 
according to law, or which is contained in packages not branded 
or marked according to law, shall be liable to a penalty of fifty 
dollars for each such offense. 

Sec. 13. That every person who knowingly purchases or receives 
for sale any filled cheese from any manufacturer or importer who 
has not paid the special tax herein provided for shall be liable, 
for each offense, to a penalty of one hundred dollars, and to a for- 
feiture of all articles so purchased or received, or of the full value 
thereof. 

Sec. 14. That whenever any stamped package containing filled 
cheese is emptied it shall l)e the duty of the person in whose 



Dairy Laws. 251 

hands the same is to destroy the stamps thereon; and any person 
who willfully neglects or refuses so to do shall, for each such 
offense, be fined not exceeding fifty dollars or imprisoned not less 
than ten days nor more than six months. 

Sec. 15. That the Commissioner of Internal Revenue is author- 
ized to have applied scientific tests, and to decide whether any 
substances used in the manufacture of filled cheese contain ingre- 
dients deleterious to health. But in case of doubt or contest, his 
decision in this class of cases may be appealed from to a board 
hereby constituted for the pui'pose, and composed of the Surgeon- 
General of the Army, the Surgeon-General of the Navy, and the 
Secretary of Agriculture, and the decision of this board shall be 
final in the premises. 

Sec. 16. That all packages of filled cheese subject to tax under 
this act that shall be found without stamps or marks as herein 
provided, and all filled cheese intended for human consumption 
which contains ingredients adjudged as hereinbefore provided to be 
deleterious to the public health, shall be forfeited to the United 
States. 

Sec. 17. That all fines, penalties and forfeitures imposed by this 
act may be recovered in any court of competent jurisdiction. 

Sec. 18. That the Commissioner of Internal Revenue, with the 
approval of the Secretary of the Treasury, shall make all need- 
ful regulations for the caiTying into effect the provisions of this 
act. 

Sec. 19. That this act shall go into effect on the ninetieth day 
after its passage, and all wooden packages containing ten or more 
pounds of filled cheese found on the premises of- any dealer on 
and after the ninetieth day succeeding the date of the passage of 
this act, shall be deemed to be taxable under section nine of this 
act, and shall be taxed, and shall have afiixed thereto the stamps, 
marks, and brands required by this act or by regulations made 
pursuant to this act; and for the purpose of securing the affixing 
of the stamps, marks, and brands required by this act, the filled 
cheese shall be regarded as having been manufactured and sold or 
removed from the manufactory for consumption or use on or after 
the day this act takes effect; and such stock on hand at the time 
of the taking effect of this act may be stamped, mai'ked, and branded 
under special regulations of the Commissioner of Internal Revenue, 
approved by the Secretary of the Treasury; and the Commissioner 



252 Millc and Its Products. 

of Internal Revenue may authorize the holder of such packages to 
mark and brand the same and to afl&x thereto the proper tax-paid 
stamps. 

Approved June 6, 1896. 

THE NEW YORK LAW. 

The law of the state of New York is typical of the state laws 
governing the manufacture, sale, and adulteration of dairy products. 
It forms Article II. of Chapter XXXIII. of the General Laws; the 
latter being Chapter 338 of the Laws of 1893, passed April 10th, 
1893, and is as follows: \ 

ARTICLE II. 

Dairy Products. 

Sec. 20. Definitions. — The terms butter and cheese, when used 
in this article, mean the products of the dairj^, usually known by 
those terms, which are manufactured exclusively from pure, una- 
dulterated milk or cream or both, with or without salt or rennet, 
and with or without coloring matter or sage. The terms oleomar- 
garine, butterine, imitation butter or imitation cheese, shall be 
construed to mean any article or substance in the semblance of 
butter or cheese not the lasual product of the dairy, and not made 
exclusively of pure and unadulterated milk or cream, or any such 
article or substance into which any oil, lard or fat not produced 
from milk or cream enters as a component part, or into which 
melted butter or butter in any condition or state, or any oil 
thereof, has been introduced to take the place of cream. The term 
adulterated milk, when so used, means: 

1. Milk containing more than 88 per centum of water or fluids. 

2. Milk containing less than 12 per centum of milk solids. 

3. Milk containing less than 3 per centum of fats. 

4. Milk drawn from cows within fifteen days before and five 
days after parturition. 

5. Milk drawn from animals fed on distillery waste, or any sub- 
stance in a state of fermentation or putrefaction, or on any un- 
healthy food. 

6. Milk drawn from cows kept in a crowded or unhealthy con- 
dition. 



Dairy Laws. 253 

7. Milk from which any part of the cream has been removed. 

8. Milk which has been diluted with water or any other fluid, 
or to which has been added or into which has been introduced 
any foreign substance whatever. 

All adulterated milk shall be deemed unclean, unhealthy, impure 
and unwholesome. The tei-ms pure milk or unadulterated milk, 
when used singly or together, mean sweet milk not adulterated, and 
the terms pure cream or unadulterated cream, when used singly 
or together, mean cream taken from pure and unadulterated milk. 

Sec. 21. Cai-e and feed of eotvs. — No person shall keep cows, 
for the production of milk for market or for sale or exchange, 
or for manufacturing the milk or cream from the same into any 
article of food, in a crowded or unhealthy condition, or feed any 
such cows on distillery waste or on any substance in a state of 
putrefaction or fermentation, or upon any food that is unhealthj-, 
or that produces impure, unhealthy, diseased or unwholsome milk. 
But this section shall not be construed to prohibit the feeding of 
ensilage. 

Sec. 22. Prohibition of the sale of adulterated milk. — No person 
shall sell or exchange, or offer or expose for sale or exchange, 
any unclean, impure, unhealthy, adulterated or unwholesome milk 
or any cream from the same, or sell or exchange, or offer or expose 
for sale or exchange, any article of food made from such milk, or 
of or from cream from the same, or manufacture from any such 
milk or cream from the same, any article of food. 

Sec. 23. Regulations in regard to butter and cheese factories. — 
No person shall sell, supply or bring to be manufactured to any 
butter or cheese factory any milk diluted with water, or any un- 
clean, impure, unhealthy, adulterated or unwholesome milk, or milk 
from which any of the cream has been taken, except pure skim 
milk to skim-cheese factories. No person shall sell, supply or 
bring to be manufactured to any butter or cheese factory any milk 
fi'om which there has been kept back any part of the milk com- 
monly known as strippings, or any milk that is sour, except pure 
skim milk to skim-cheese factories. The owner or proprietor, or the 
persons having charge of any butter or cheese factory, not buying 
all the milk used by him, shall not use for his own benefit, or 
allow any of his employes or any other person to use for his own 
benefit, any milk, cream, butter or cheese or any other product 
thereof, brought to such factory, without the consent of the own- 
ers of such milk or the products thereof. Every butter or cheese 



254 Milk and Its Prodvcts. 

manufacturer not buying all the milk he uses, shall keep a cor- 
rect account of all the milk daily received, of the number of 
packages of butter and cheese made each day, and the number of 
packages and aggregate weight of cheese and butter disposed of 
each day ; which account shall be open to inspection to any per- 
son who delivers milk to such factory. 

Sec. 24. Cans to be branded with the name of county. — No 
person shall sell or offer or expose for sale or exchange any milk, 
except in the county where produced, unless each can, vessel or 
package containing such milk shall be distinctly and durably branded 
with letters not less than one inch in length and of a suitable 
width to correspond with such length, and with suitable spaces be- 
tween the letters, on the outside, above the center, on every can, 
vessel or package containing such milk, the name of the county 
from which the same is produced ; and the same letters shall be 
branded or painted in a conspicuous place on the carriage or 
vehicle in which the milk is drawn to be sold ; and such milk 
shall not be sold by the producer outside of the county in which 
it is produced, except in or out of a can, vessel, package or car- 
riage or vehicle so marked. The foregoing prohibitions and provi- 
sions of this section shall not apply when milk is sold or delivered 
in glass bottles. No milk shall be sold or delivered in glass bot- 
tles, except in the county where produced, unless such bottles 
shall have legibly blown, stamped, engraved, etched, impressed or 
moulded in the glass, or otherwise produced upon such bottles, the 
name of the vendor, or the same is on a label or cover affixed 
thereto, or there is some mark or device on or affixed to such 
bottles by which the vendor may be ascertained. 

Sec. 25. Regulations in regard to condensed milk. — No condensed 
milk shall be made or offered or exposed for sale or exchange un- 
less manufactured from pure, clean, healthy, fi-esh, unadulterated 
and wholesome milk from which the cream has not been removed 
either wholly or in part, or unless the proportion of milk solids 
shall be in quantity the equivalent of 12 per centum of milk 
solids in crude milk, and of which solids 25 per centum shall be 
fats. No person shall manufacture, sell or offer for sale or ex- 
change in hermetically sealed cans, any condensed milk unless put 
up in packages upon which shall be distinctly labeled or stamped 
the name of the person or corporation by whom made, and the 
brand by which or under which it is made. When condensed milk 
shall be sold from cans or packages not hermetically sealed, the 



Dairy Laws. 255 

vendor shall brand or label such cans or packages with the name 
of the manufacturer of the milk contained therein. 

Sec. 26. Manufacture and sale of imitation butter prohibited. — 
No person, by himself, his agents or employes, shall produce or 
manufacture out of or from any animal fats or animal or vegetable 
oils not produced from unadulterated milk, or ci-eam from the same, 
any article or product in imitation or semblance of natural butter 
produced from pure, unadulterated milk or cream of the same ; nor 
shall any person solicit or take oi'ders for the same, or offer the 
same for sale, or mix, compound with or add to milk, cream or 
butter any acids or other deleterious substance, or any animal fats 
or animal or vegetable oils not produced from milk or cream, so 
as to produce any article or substance, or any human food in imi- 
tation or in semblance of natural butter, nor sell, keep for sale or 
offer for sale any article, substance or compound made, manufac- 
tured or produced in violation of the provisions of this section, 
whether such article, substance or compound shall be made or pro- 
duced in this state or elsewhere. 

Sec. 27. Manufacture of* mixing of animal fats tvith milk, 
cream or butter prohibited. — No person shall manufacture, mix, or 
compound with or add to natural milk, cream or butter any ani- 
mal fats or animal or vegetable oils, nor make or manufacture any 
oleaginous substance not produced from milk or cream, with intent 
to sell the same as butter or cheese made from unadulterated milk 
or cream or have the same in his possession with such intent ; nor 
shall any person solicit or take orders for the same or offer the 
same for sale, nor shall any such article or substance or compound, 
so made or produced, be sold as and for butter or cheese, the pro- 
duct of the dairy. No person shall coat, powder or color with 
annatto or any coloring matter whatever, butterine or oleomargarine 
or any compound of the same, or any product or manufacture 
made in whole or in part from animal fats or animal or vege- 
table oils not produced from unadulterated milk or cream by means 
of which such product, manufacture or compound shall resemble 
butter or cheese, the product of the dairy ; nor shall he have the 
same in his possession with intent to sell the same, nor shall he 
sell or offer to sell the same. 

Sec. 28. Prohibited articles not to be furnished. — Nor keeper or 
proprietor of any bakery, hotel, boarding-house, restaurant, saloon, 



*So in the original. 



256 ■ Millc and Ifs Products. 

lunch-counter or place of public entertainment, or any person hav- 
ing charge thereof or employed thereat, or any person furnishing 
board for any others than members of his own family, or for any 
employes where such board is furnished for a compensation or as 
part of the compensation of any such employe, shall keep, use or 
serve therein, either as food for his guests, boarders, patrons, cus- 
tomers or employes, or for cooking purposes, any article or sub- 
stance made in violation of the provisions of this article. 

Sec. 29. Use of coloring matter prohihited. — No person manu- 
facturing with intent to sell any substance or article in imitation 
or semblance of butter or cheese not made exclusively from un- 
adulterated milk or cream, or both, with salt or rennet, or both, and 
with or without coloring matter or sage, but into which any animal, 
intestinal or offal fats, or any oils or fats or oleaginous substance 
of any kind not produced from from* pure, unadulterated milk or 
cream, or into which melted butter, or butter in any condition or 
state or any modification of the same, or lard or tallow shall be 
introduced, shall add thereto or combine therewith any annatto or 
compounds of the same, or any other substance or substances what- 
ever, for the purpose or with the effect of imparting thereto a 
color resembling yellow, or any shade of yellow butter or cheese, 
nor introduce any such coloring matter or other substance into any 
of the articles of which the same is composed. 

Sec. 30. Manufacture and sale of imitation cheese prohibited. — No 
person shall manufacture, deal in, sell, offer or expose for sale or 
exchange any article or substance, in the semblance of or in imi- 
tation of cheese made exclusively of unadulterated milk or cream, 
or both, into which any animal, intestinal or offal fats or oils, or 
melted butter or butter in any condition or state or modification of 
the same, or oleaginous substances of any kind not produced from 
unadulterated milk or cream, shall be introduced. 

Sec. 31. When prohibitions do not apply to skim milk or skim 
cheese. — Except in the counties of New York and Kings, the pro- 
hibitions contained in this article against the sale of adulterated 
milk shall not apply to skim milk which is clean, pure, healthy, 
wholesome and unadulterated, except by skimming, sold for use in 
the county in which it is produced or an adjoining county, if it 
is sold for and as skimmed milk. The prohibitions in this article 
against the sale of cheese made from unadulterated milk or cream 



*So in the original. 



Dairy Laws. 257 

shall not apply to pure skim cheese made from milk which is 
clean, pure, healthy, wholesome and unadulterated, except by skim- 
ming. 

Sec. 32. Packages to be branded with name of maker. — No man- 
ufacturer of receptacles for the package of butter shall sell or dis- 
pose of any such receptacle without branding his name and the 
true weight of the receptacle upon the same with legible letters or 
figures not less than one-quarter of an inch in length. No person 
shall sell, or offer for sale, any package containing butter or lard 
packed by him unless the true weight thereof, with the initial let- 
ters of the name of the person packing such butter or lard, be 
marked or stamped in a legible manner on the side or head of such 
package. 

Sec. 33. Manufacturer's brand of cheese. — Every manufacturer 
of full milk cheese may put a brand upon each cheese indicating 
"full milk cheese," and the date of the month and year when 
made, and no person shall use such a brand upon any cheese made 
from milk from which any of the cream has been taken. The 
Commissioner of Agriculture shall procure and issue to the cheese 
manufacturers of the state, on proper application therefor, and under 
such regulations as to the custody and use thereof as he may pre- 
scribe, a uniform stencil brand, bearing a suitable device or motto, 
and the words, "New York state full cream cheese." Every such 
brand shall be used upon the outside of the cheese and upon the 
package containing the same, and shall bear a different number for 
each separate factory. The Commissioner shall keep a book, in 
which shall be registered the name, location and number of each 
manufactory using the brand, and the name or names of the per- 
sons at each manufactory authorized to use the same. No such 
brand shall be used upon any other than full-cream cheese or pack- 
ages containing the same. 

Sec. 34. Use of false brand prohibited.— 'i^o person shall offer, 
sell, or expose for sale, in any package, butter or cheese which is 
falsely branded or labeled. 

Sec. 35. County trade-marks. — At a regular or special meeting 
of a county dairyman's association in any county of the state there 
may be adopted a county trade-mark, by a majority of the mem- 
bers present and voting, to be used as a trade-mark by am* 



*So in the original. 



258 Milk and Its Products. 

person manufacturing pure unadulterated butter or full-cream cheese 
in such county. The secretary of the association shall forthwith 
send to the Commissioner of Agriculture a copy of such trade-mark, 
which copy he shall place on file in his office, noting thei'eupon the 
day and hour he received the same. But one county trade-mark 
for butter and for cheese shall be placed on file for the same 
county. No association shall adopt any trade-mark of any county 
already on file, or use that of any other county in the formation 
of a trade-mark. 

Sec. 36. Object and intent of this article. — This article and each 
section thereof are declared to be enacted to prevent deception in 
the sale of dairy products, and to preserve the public health, which 
is endangered by the manufacture, sale and use of the articles or 
substances herein regulated or prohibited. 

Sec. 37. Penalties. — Every person violating any of the provisions 
of this article shall forfeit to the people of the state of New York 
the sum of one hundred dollars for every such violation. When 
such violation consists of the manufacture or production of any 
prohibited article, each day during which or any pai't of which such 
manufacture or production is carried on or continued shall be 
deemed a separate violation of the provisions of this article. When 
the violation consists of the sale, or the offering or exposing for 
sale or exchange of any prohibited article or substance, the sale of 
each one of several packages shall constitute a separate violation, 
and each day on which any such article or substance is offered or 
exposed for sale or exchange shall constitute a separate violation of 
this article. When the use of any such article or substance is 
prohibited, each day during which or any part of which said article 
or substance is so used or furnished for use shall constitute a 
separate violation, and the furnishing of the same for use to each 
person to whom the same may be furnished shall constitute a 
separate violation. 



References. 259 

D. REFERENCES TO AGRICULTURAL EXPERIMENT 
STATION REPORTS AND BULLETINS. 

The following references will aid the student who desires to make 
a more thox-ough study of the subjects discussed. They are taken 
wholly from the literature of American agricultural investigations, 
and include only some of the more important articles. The Experi- 
ment Station Record and the Handbook of Experiment Station Work, 
both issued by the U. S. Department of Agriculture, contain many 
condensed results of dairy investigation. 



Chapter I. 

Studies in Milk Secretion. Indiana Bull. No. 24, pp. 13-16. 
How is Milk Formed? Nevada Bull. No. 16, pp. 4-5. 
Elaboration of Milk. Ontario Kept, for 1893, pp. 165-166. 
Dividing Milkings. Indiana Bull. No. 24, pp. 10-13. 
Milking Two and Three Times per Day. Vermont Kept, for 
1890, pp. 90-96. 

Chapter II. 

The Composition of Milk. Ontario Bull. No. XXXIX. 

The Mineral Ingredients of Milk. Maine Kept, for 1890, part 
II., pp. 52-57. 

The Constitution of Milk, and Some of the Conditions which 
Affect the Separation of Cream. Wisconsin Bull. No. 18. 

Conditions Affecting the Consistency of Milk. Wisconsin Rept. 
for 1896, pp. 73-80. 

Chemistry of Dairy Products. Ontario Rept. for 1890, pp. 237-241. 

Milk Analysis. Connecticut Rept. for 1886, pp. 119-1.30. 

Investigations Relating to the Composition of Milk. Wisconsin 
Rept. for 1890, pp. 114-119. 

Fibrin in Milk. Wisconsin Rept. for 1893, pp. 143-145. 

Relation of Fat and Casein in Milk. Vermont Rept. for 1890, pp. 
97-100. 

The Composition, Creaming and Churning of Colostrum. Vermont 
Rept. for 1891, pp. 104-108. 

The Fat Globules of Milk. New York for Rept. 1885, pp. 266- 
275; Wisconsin Rept. for 1894, pp. 223-239; Ontario Rept. for 1885, 
pp. 127-130. 

B 



260 Milk and Its Products. 

The Effects of Feed Upon the Quality of Milk. Iowa Bull, No. 14, 
pp. 123-142 ; New Hampshire Rept. for 1893, pp. 138-155, and Bull. 
No. 9 ; Bull. No. 16 ; Bull. No. 18 ; Bull. No. 20. 

Tests of Several Breeds of Dairy Cows. A Study of Dairy Pro- 
ducts. Maine Rept. for 1889, pp. 106-134. The test is continued in 
Rept. for 1890, Part II., pp. 17-42. 

Corn Silage for Milch Cows. New York (State) Bull. No. 97, 
New Series. 

Investigations of the Several Breeds of Dairy Cattle. New York 
(State) Reports for 1891, 1892, 1893, 1894. 

On the Effects of Feeding Fat to Cows. New York (Cornell) 
Bull. No. 92. 

Variations in Milk. Illinois Bull. No. 17, pp. 9-16, and Bull. No. 24. 

The Influence of Advancing Lactation upon the Production of But- 
ter and Cheese. New York (State) Rept. for 1891, pp. 369-389. 

Effects of Drouth upon Milk Production. New York (State) Bull. 
No. 105. New Series. 

Variations in Milk. Vermont Rept, for 1891, pp. 61-74. 

Variations in Quantity and Quality of Milk. Vermont Rept. for 
1892, pp. 90-119, and Bull. No. 38. 

The Composition of Milk as Affected by Methods of Milking. 
Wisconsin Rept. for 1889, pp. 44, 51, 61. 

Chapter III. 

Milk Tests. (Short, Lactoscope.) Illinois Bull. No. 9, pp. 293-302. 

Investigation of Milk Tests, (Short, Parsons, Failyer and Willard, 
Cochran, Patrick,) Illinois Bull, No. 10. 

Milk Tests : Methods of Testing Milk. (Patrick, Babcock, Beim- 
ling, Gravimetric.) Illinois Bull. No. 14, pp. 462-467. 

Methods of Testing Milk. (Short, Patrick, Cochran, Babcock, 
Beimling.) West Virginia Bull. No. 13, pp. 41-63. 

Testing Milk. (Short, Pati'ick, Cochran, Babcock, Soxhlet, Beim- 
ling.) West Virginia Report for 1890, pp. 68-88. 

A New Volumetric Method for the Estimation of Fat in Milk, 
Skimmed Milk, Buttermilk and Cream. (Parsons,) New Hampshire 
Report for 1888, pp. 69-83. 

Babcock and Beimling Tests, Ontario Report for 1891, pp, 183- 
184. 

Simple Methods of Determining Milk Fat. (Short, Cochran, Gravi- 
metric) Pennsylvania Bull, No. 12. 



Referenced. 261 

Comparative Test of Machines and Methods for the Determination 
of Fat in Milk. (Short, Beimling, Patrick, Babcock, Gravimetric.) 
Mississippi Bull. No. 15, pp. 5-16. 

A Description of Cochran's Method for the Determination of Fat 
in Milk, for the Use of Dairymen. New York (Cornell) Bull. No. 
XVII. 

Iowa Station Milk Test. (Patrick). Iowa Bull. No. 8, pp. 295- 
316 ; No. 9, p. 355 ; No. 11, pp. 484-487. 

A New Method for Determining the Amount of Butter Fat in 
Milk. Mississippi Bull. No. 21, pp. 17-19. 

A New Milk Test. (Beimling). Vermont Bull. No. 21. 
The Lactanalyt, A New Milk Tester. Vermont Report for 1894, 
pp. 161-162. 

A New Method of Milk Analysis (Short) for the Use of Dairy- 
men, and a Comparison of Its Results with those Obtained by the 
Churn. Kansas Report for 1888, pp. 149-164. 

A Method for the Determination of Fat in Milk and Cream. 
(Parsons.) New York (State) Bull. No. 19. New Series. 

Feser's Lactoscope and Fjord's Centrifugal Controller, described 
in Ontario Report for 1885, pp. 207-208. 

Testing Milk at Creameries, (Short.) Vermont Bull. No. 16. 
The Schoch and Bolender Test Churn. Wisconsin Report for 
1884, pp. 23-25. 

Description of the Test Churn. Ontario Report for 1885, p. 201. 
The Oil Test for Cream. Wisconsin Bull. No. 12. 
A New Method for Determining Fat in Milk. (Short.) Wiscon- 
sin Bull. No. 16 and Report for 1888, pp. 124-136. 

The Babcock Milk Test was first described in Wisconsin Bull. 
No. 24 and Report for 1890, pp. 98-113. Improvements and modifi- 
cations are discussed in Bull. No. 31, pp. 3-16 ; Bull No. 36, pp. 
3-20 ; Bull No. 52, Report for 1892, pp. 219-244 ; Report for 1893, 
pp. 116-121. Compared with the Gravimetric Method in Report for 
1896, pp. 138-143. 

Elsewhere, the method has been described in Pennsylvania Bull. 
No. 33; Washington Bull. No. 18; New York (Cornell) Bull. No. 29, 
pp. 77-80 ; Colorado Bull. No. 20, pp. 3-10 ; North Carolina Bull. No. 
113, pp. 101-111 ; West Virginia Bull. No. 13, pp. 52-57 ; Ontario Bull. 
No. LXI. ; Bull. No. XCIIL, pp. 5-6 ; Connecticut Bull. No. 106, pp. 
2-9 ; Bull No. 108, pp. 5-11 ; Bull No. 117, Report for 1894, pp. 209- 
244 ; Maine Bull. No. 3, Second Series ; Bull No. 4, Report for 1891, 
Part II., pp. 71-80; Michigan Bull. No. 127; Illinois Bull. No. 27; 
North Dakota Bull. No. 22 ; Pennsylvania Report for 1895, Part II., 



262 Milk and Its Products. 

pp. 90-100 ; Nevada Bull. No. 16, pp. 41-51 ; Mississippi Bull. No. 15, 
pp. 7-14. 

Milk Sampling. Delaware Bull. No. XXXI. 

Composite Milk Samples Tested tot Butter Fat. Illinois Bull. 
No. 16, pp. 504-515. Continued in Bull. No. 18, pp. 27-28. 

The Composite Sample. Preservatives for Keeping Milk — Samples 
for Testing. Iowa Bull. No. 11, pp. 482-484. 

Composite Samples at the Creamery — Chromate Preservatives, 
Iowa Bull. No. 22, pp. 836-844. 

Detection of Adulterations in Milk. Wisconsin Bull. No. 31, pp. 
17-27; Bull. No. 36, pp. 21-31, and Report for 1892, pp. 245-257. 
Ontario Bull. No. XCIII., pp. 3-5; Vermont Newspaper Bull. No. 4. 

Lactometer and Milk Test for Examining Milk. Minnesota Bull. 
No. 27, pp. 55-56. 

The Relation between Specific Gravity and Solids of Milk. Wis- 
consin Report for 1895, pp. 120-126. 

The Estimation of the Total Solids in Milk from the Per Cent 
of Fat, and the Specific Gravity of the Milk. Wisconsin Repoi't for 
1891, pp. 292-307, and Report for 1893, p. 142. 

The Lactometer and Fat Test for Cheese and Condensed Milk 
Factories Maine Bull. No. 4, New Series, pp. 6-10. 

Chapter IV. 

Dairy Bacteriology. U. S. Dept. Agr. Ofiice of Expt. Stations. 
Bull. No. 25. 

The Fermentations of Milk. U. S. Dept. Agr. Expt. Stations. 
Bull. No. 9. 

Souring of Milk. U. S. Dept. Agr. Farmers' Bull. No. 29. 

Milk Fermentations and Their Relations to Dairying. U. S. Dept. 
Agr. Farmers' Bull. No. 9. 

The Isolation of Rennet from Bacteria Cultures. Connecticut 
(Storrs) Report for 1892, pp. 106-126. 

The Sources of Bacterial Infection, and the Relation of the Same 
to the Keeping Quality of Milk. Wisconsin Report for 1894, pp. 
150-165. 

Cleanliness in Handling Milk ; Bactei'iological Considerations. 
North Dakota Bull. No. 21. 

A Microccus of Bitter Milk. Connecticut (Storrs) Report for 
1891, pp. 158-162. 

Pasteurization of Milk and Cream for Direct Consumption. Wis- 
consin Bull. No. 44. 



References. 263 

Notes on Pasteurization of Milk and Cream. Wisconsin Report 
for 1895, pp. 158-173. 

On the Restoration of tlie Consistency of Pasteurized Milk aud 
Cream. Wisconsin Report for 1896, pp. 81-94, and Bull. No. 54. 

A Preliminary Bulletin on Pasteurization of Milk. Michigan Bull. 
No. 134. 

Preservation of Cream for Market. Maine Bull. No. 23, New 
Series. 

Chapter V. 

Aeration and Aerators. New York (Cornell) Bull. No. 39, pp. 
90-94. 

Aeration of Milk. Vermont Report for 1892, pp. 123-128. 

Concerning the Aeration of Milk. Indiana Bull. No. 44, pp. 37-39. 

Town and City Milk Supply. U. S. Dept. Agr. Farmers' Bull. 
No. 42, pp. 23-28. 

Variations in Fat of Milk Served to Customers in Dipping from 
Cans. New York (Cornell) Bull. No. XX., pp. 68-71. 

Variations in the Fat of Milk. Ontario Bull. No. LXVI. 

Chapter VI. 

Cream Raising by Dilution. New York ( Cornell ) Bull. No. 20, 
pp. 61-67; Bull. No. 29, pp. 65-71|; Bull. No. 39, pp. 77-85; Illinois 
Bull. No. 12, pp. 376-377 ; Bull. No. 18, pp. 30-32 ; Vermont Rept. for 
1890, pp. 100-107. 

Other Methods of Setting Milk. Minnesota Bull. No. 19, pp. 11- 
19; Iowa Bull. No. 25, pp. 39-40; Indiana Bull. No. 44, pp. 23-37; Wis- 
consin Rept. for 1884, pp. 17-22 ; Rept. for 1893, pp. 147-150 ; Bull. 
No. 7, pp. 9-13 ; Bull. No. 29 ; Canada, Central Experimental Farm 
Rept. for 1891, pp. 89-104 ; Rept. for 1892, pp. 71-74 ; Ontario Rept. 
for 1894, pp. 142-144 ; Vermont Rept. for 1891, pp. 100-101 ; Maine 
Bull. No. 5, Second Series ; Utah Bull. No. 42. 

The Viscosity of Milk. New York (State) Rept. for 1886, pp. 32.3-330. 

The Constitution of Milk, and Some of the Conditions Which Affect 
the Separation of Cream. Wisconsin Bull. No. 18. 

The Centrifugal Separation of Casein and Insoluble Phosphates from 
Milk. Wisconsin Rept. for 1895, pp. 93-99. 

Tests of Cream Sepai-ators. Delaware Bull. No. 17, and Rept. for 
1892, pp. 110-122 ; Iowa Bull. No. 25, pp. 32-38 ; New Hampshire Rept. 
for 1893, pp. 36-45 and Bull. No. 7; New York (Cornell) Bull. No. 66 
?indl05; North Carolina Bull. No. 114; Pennsylvania Rept. for 1892 



264 Milk and Its Products. 

part II., pp. 51-79, and Bull. No. 20; Bull. No. 27, Rept. for 1894, 
pp. 13-35; South Dakota Bull. No. 39; Vermont Bull. No. 27, and 
Rept. for 1892, pp. 136-143; Rept. for 1893, pp. 92-100; Rept. for 
1894, pp. 151-160; Wisconsin Rept. for 1895, pp. 151-157, and Bull. 
No. 46 



Chapters VII., VIII., IX. 

Experiments with Boyd's Vat and Starter. Ontario Rept. for 1891, 
pp. 178-179. 

Bacteria in the Dairy. Connecticut (Storrs) Rept. for 1895, pp. 
14-41. 

The Use of Bacterial Culture Starters in Butter Making, With 
Especial Reference to the Conn Culture ( B. 41). Wisconsin Rept. for 
1895, pp. 174-231; published, in part, in Bull. No. 48. 

An Acid Test of Cream. Illinois Bull. No. 32, and Bull. No. 33, 
pp. 399-400. 

The Alkaline Tablet Test of Acidity in Milk or Cream. Wisconsin 
Bull. No. 52, pp. 8-16. 

Sweet Versus Sour Cream Butter. Iowa Bull. No. 8, pp. 317-320; 
Bull. No. 11, pp. 481-482 ; Bull. No. 18, pp. 478-487 ; Bull. No. 21, pp. 
788-791; Illinois Bull. No. 9, pp. 301-302; Texas Bull. No. 11, pp. 
15-16; Ontario Rept. for 1891, pp. 179-181; West Virginia Rept. for 
1890, pp. 48-66. 

Creamery Studies of Methods and Machinery. A comparison 
of the Sour Cream, Sweet Cream and Butter Extractor Processes. 
Delaware Rept. for 1890, pp. 17-23, and pp. 129-149; also Bull. 
No. IX. 

Our Experience with Extractor Butter. Ontario Rept. for 1893, 
pp. 170-171. 

A Study in Churning. Iowa Bull. No. 22, pp. 819-832. 

Churning Experiments. Vermont Rept. for 1893, pp. 100-106. 

Butter Tests. New York (State) Rept. for. 1884, pp. 334-347, and 
Rept. for 1885, pp. 275-292. 

The Effect of Succulent Food Upon the Churnability of the Fat in 
Milk. Vermont Rept. for 1890, pp. 70-74. 

Butter Making. Ontario Rept. for 1889, pp. 161-163; Bull. No. 
XLVIII. 

Canada Central Experimental Farm Dairy. Bull. No. 3. 

Washing and Salting Butter. Minnesota Bull. No. 7, pp. 34-42. 



References. 265 

Chaptbbs X., XI. 

For references to aeration, see Chapter V. 

. Points of Attention for the Patrons of Cheese Factories and Cream- 
eries. Ontario Bull. No. II. 

Milk for Cheese Making. Ontario Bull. No. XLI.; Bull. No. 
XXVIII.; Bull. XCIV. ; Canada Central Experimental Farm Dairy. 
Bull. No. 1. 

Pure Lactic Culture of Bacteria in Cheese Making. Wisconsin Rept. 
for 1896, pp. 112-12G. 

Rennet Extracts of Commerce. Iowa Bull. No. 22, pp. 845-851. 

Losses in Cheese Making. Vermont Rept. for 1891, pp. 95-100. 

The Effect of Salt Upon Cheese. Wisconsin Rept. for 1894, pp. 
220-222. 

The Effect of Aeration on the Flavor of Tainted Curds in Cheese 
Making. The Influence of Acid on the Texture of Cheese. The Hot 
Ii'on Test. Experiments in Ripening the Milk before Setting. Wis- 
consin Rept. for 1895, pp. 127-138. 

Experiments in the Manufacture of Cheese. New York ( State ) 
Repts. for 1891, p. 216; 1892, p. 295; 1893, p. 239; 1894, p. 263. 

Hints to Cheese Makers. Iowa Bull. No. 19, pp. 627-631. 

Investigations in Cheese Making. Iowa. Bull. No. 21, pp. 735-767. 

Experiments in Cheese Making. Minnesota Bull. No. 19, pp. 
20-25. 

Experiments in the Manufacture of Cheese. Wisconsin Rept. for 
1894, pp. 131-149. 

The Relation Between Milk Solids and the Yield of Cheese. Wis- 
consin Rept. for 1895, pp. 100-119. 

Notes for Cheese Makers for May. Ontario Bull. No. XL. ; for July, 
Bull. No. XLIIL; for August, Bull. No. XLIV.; for October, Bull. 
No. XLVII. Rept. for 1889, pp. 163-179. 

Notes for Cheese Makers for May. Canada Central Experimental 
Farm, Dairy Bull. No. 2; Special Dairy Bulletins for July, August, 
October and June. 

Articles on Spring, Summer and Fall Cheese in Ontario Rept. for 
1893, pp. 167-170. 

Gas Producing Bacteria, and the Relation of the Same to Cheese. 
Wisconsin Rept. for 1895. 

The Rise and Fall of Bacteria in Cheddar Cheese. Wisconsin Rept. 
for 1896, pp. 95-111. 

An Aromatic Bacillus of Cheese. Iowa Bull. No. 21, pp. 792-796. 

Changes During Cheese Ripening. Iowa Bull. No. '24, pp. 969-984. 



266 Milk and Its Products. 

Moisture Supply in Cheese Curing Rooms. Wisconsin Rept. for 
1896, pp. 156-163. 

Experiments Upon the Curing of Cheese. Cornell University Agr. 
Exp. Sta. Rept. for 1880, pp. 9-27. 

Chapter XII. 

The Manufacture of Sweet Curd Cheese (Edam and Gouda). Min- 
nesota Rept. for 1894, pp. 104-128, and Bull. No. 35. 

Experiment Relating to the Manufacture of Edam and Gouda Cheese. 
New York (State) Rept. for 1893, pp. 244-269, and Bull. No. 56. 

Albumin Cheese. Wisconsin Rept. for 1895, pp. 134-136. 

Chapter XIII. 

The Manufacture of Milk Sugar (Report of Chemist). Delaware 
Report for 1891, pp. 104-108. 

The Hog as an Adjunct to the Dairy. Ontario Report for 1889, 
pp. 184-189. 

Whey Butter. New York (Cornell) Bull. No. 85. 

Sweet Skim Milk ; Its Value as Food for Pigs and Calves. 
Wisconsin Bull. No. 1. 

The Feeding Value of Whey. Wisconsin Bull. No. 27, Report 
for 1891, pp. 38-48. 

Feeding Waste Products of the Dairy. Wisconsin Report for 
1886, pp. 21-25. 

The Value of Creamery Separator Skim Milk for Swine Feeding. 
Wisconsin Report for 1895, pp. 7-23. 



Chapter XIV. 

Building Creameries and Organization of Cooperative Creamery 
Companies. South Dakota Bull. No. 46. 

Creameries for Texas ; Plans and Specifications in Full for Cream.- 
ery Outfit. Texas Bull. No. 5. 

Cooperative Creameries. Minnesota Report for 1894, pp. 93-103, 
and Bull. No. 35. 

The Establishment of Cheese Factories and Creameries. Special 
Bull, of the Central Canada Experimental Farm, Ottawa. 

By-Laws, Rules and Regulations for Cheese Factories. Canada 
Central Experimental Farm Dairy Bull. No. 9. 



References. 267 

By-Laws, Rules and Regulations for Creameries on the Cream- 
Gathering Plan. Central Experimental Farm, Dairy Bull. No. 10. 

Chapter XV. 

Statistics of the Dairy. U. S. Dept. Agr., Bureau of Animal In- 
dustry. Bull. No. 11. 

Returns from the Ninth, Tenth and Eleventh Censuses, Relating 
to the Production of Milk, Butter and Cheese on the Farm. U. S. 
Dept. Agr., Report of the Statistician, No. 113, pp. 115-118. 

General. 

Facts About Milk. U. S. Dept. Agr., Farmers' Bull. No. 42. 

The Dairy Industry in Denmark. U. S. Dept. Agr., Bureau of 
Animal Industry, Bull. No. 5. 

The Creamery Industry. Nevada Bull. No. 16. 

Dairying. South Carolina Bull. No. 19. 

Dairying in California. U. S. Dept. Agr., Bureau of Animal In- 
dustry, Bull. No. 14. 

Dairy Farming in Washington. Washington Bull. No. 2, pp. 23-27. 

The Dairy Industry in Nebraska, South Dakota and North Dakota. 
Q. S. Dept. Agr., Bureau of Animal Industry, Bull. No. 16. 



INDEX. 



PAGE 

Abnormal fermentations 69 

Accumulator 117 

Accuracy of Babcock test glass- 
ware 55 

Acid, boracic 77 

— citric 25 

— hydrochloric, for ripening cream . 123 

— lactic 24, 72, 124 

— — determination of 129, 233 

— oleic 22 

— palmitic 22 

— salycilic 77 

— stearic 22 

— sulphuric 60 

— test, Manns' 128 

Acini 3 

Act, Filled cheese 229, 240 

— oleomargarine 228, 230 

Adams' method 34 

Adjustable separator 117 

Aeration of milk 84, 166 

Aerators, milk 85 

Aerometer, Soxhlet's 43 

Agricultural Experiment Station 

Bulletins 259 

— — — mentioned 44 

Air drainage 210 

Albumin 23 

Albuminoids 23 

Alcoholic fermentation 69 

Alexandra Jumbo separator 118 

Aliquot milk sampler 58 

Alkali, decinormal 129, 233 

_ ^ 129 

10 

— use of in cleaning 83 



PAGE 

Alkaline tablets, Farrington's 79 

129, 233 
Alpha discs or plates 113 

— separator 118 

Alveoli 3 

American cheddar cheese 172 

— Home-trade cheese 192 

— Neuf ehatel cheese 195 

Amphoteric reaction 64 

Analysis, gravimetric 33 

Angus, J. J., mentioned 207 

Animal excrement, relation of 

bacteria to 75 

— odor 84 

Annatto 155 

Antiseptics 76 

Apparatus, Fjord's control 43 

— pasteurizing 79 

Arnold, L. B., quoted 99 

Arnold's separator 117 

Asbestos method of determination 

of fat 34 

Ash of milk 25 

Asses' milk 16 

Associated dairying 223 

B41 125 

Babcock, Dr. S. M., mentioned.. 45, 47 
quoted 17,99,160,227 

— asbestos method 34 

— formula for solids not fat 232 

— test 47 

— — calibration of glassware 235 

— — details 50 

Bacillus 65 

— acidi laetici 71 



(269) 



270 



Index. 



PAGE 

Bacillus No. 41 125 

— prodigiosus 70 

— tubercle 78 

Bacteria 65 

— in milk 67 

— relation of animal excrement to . 75 

— — — dust to 75 

— — to hay and dried forage 75 

Barber, quoted 126 

B. and W. test bottle 52 

Beimling, H. F., mentioned 48 

— test 48 

Bernstein, A., mentioned 208 

Bichromate of potash 57 

Bitter milk 69 

Black specks in Babcock test 61 

Blood, relation of to milk secretion. 11 

"Bloody bread" 70 

Board of Health lactometer ....36, 23i 

Boracic acid 77 

Borden, Gail, Jr., mentioned 226 

Bottle, Babcock test 52 

Bottling milk 88 

"Breaking" of butter ., .140 

Breed, influence of on composition 

of milk 31 

Brie cheese 202 

Brine-salting biitter 151 

BroTvn separator, medium 117 

Bulletins and reports of Agr. Expt. 

Stations 259 

Buildings, farm dairy 218 

Burette 130 

Butter accumulator 117 

— and cheese factories, combined. .217 

— "breaking" of 140 

-— color 155 

— composition of 153 

— estimation of fat in, by Babcock 

test 54 

— factories 209 

— finish 156 

— flavor 154 

— granules, size of 145 

Buttermilk 204 



PAGE 
Buttermilk, characteristic appear- 
ance of 141 

— separation of, from butter 144 

Butter, mottled and streaked 150 

— packages 152 

— packing and marketing 151 

— prints 153 

— quality of 153 

— rancid 20 

— relation of lactic acid to keep- 

ing quality 131 

— — — wash-water to flavor 147 

— — — — — to texture 146 

— salting 148 

— scale of perfection 157 

— sweet cream 122, 131 

— texture of 122, 154 

— washing 144 

— white specks in 132 

— working 147 

Butyric acid 20 

— fermentations 69, 74 

Butyrin 20 

Butyrometer 49 

Calibration of Babcock test glass- 
ware 55, 235 

Camembert cheese 203 

Canadian Club cheese 199 

Caprin 20 

Caprilin 20 

Caproin 20 

Careno, mentioned 26 

Casein 23 

— coagulation of 158 

— formation of 8 

Catistic potash 58 

— soda 58 

Cement floors 213 

Centigrade thermometer 231 

Centrifugal force, relation of to 

complete creaming 109 

— separation 106 

— — theory of 107 

— system 93 

Cheddar cheese. ...,..,,,,. 172 



Index. 



271 



PAGE 

Cheddar, English 199 

Cheddaring 179 

Cheese 157 

— American home-trade 192 

— — Neuf ehatel 195 

— and butter factories combined.. 217 

— Brie 202 

— Camembert 203 

— Canadian Chib 195 

— Cheddar 172 

— Cheshire 199 

— Club-house 199 

— color of 189 

— composition of 189 

— cottage 20G 

— cream 192 

— curing 185 

— — rooms, construction of 217 

— Edam 201 

— English 199 

— — Cheddar 199 

— estimation of fat in, by Babcock 

test 54 

— Dutch 206 

— Emmenthaler 200 

— factories 209 

— — arrangement of 215 

— fiUed, law 246 

— flavor of 189 

— "flinty break" 189 

— food 207 

— formation of rind 185 

— Gloucester 199 

— Gouda 202 

— Gorgonzola 203 

— Gruyere 200 

— hard 191 

— imitation Swiss 198 

— law, fiUed 229 

— Limburger 196 

— making, cheddaring 179 

— — cooking 177 

— — cooling milk for 165 

— — curing 185 

— — ciitting 175 



PAGE 
Cheese-making, heating 177 

— — grinding 181 

— — loss of fat in 164 

— — matting 179 

— — over-ripe milk in 188 

— — • pressing 183 

— — quality of milk for 158 

— — ripening of milk for 166 

— — setting 173 

— — salting 182 

— — undesirable fermentations in. 186 

— — use of starters 169 

— Meadow Sweet 199 

— Parmesan 203 

— Philadelphia cream 196 

— pineapple 195 

— poisonous 71 

— pot 206 

— prepared ., 198 

— press 184 

— qualities of 189 

— rind 190 

— Roquefort 10, 202 

— sage 194 

— scale of perfection for 190 

— Schweitzer 200 

— skimmed 192,229 

— soft 191 

— solids concerned in making 157 

— Stilton 199 

— stirred curd 192 

— Swiss 200 

— texture of 189 

— truckle 195 

— "wet," "sloppy," or "leaky".... 194 

— whey 207 

— Wiltshire 199 

— Yovmg America 195 

Cheshire cheese 199 

Chloride of potash 25 

— of soda 25 

Chromogenic fermentations 69 

Churn, oil test 40 

— tests '^9 

Churning 134 



272 



Index. 



PAGE 
Churning, amount of motion nec- 
essary 139 

— difficult 141 

— dilution of cream 142 

— kind of agitation desirable 137 

— relation of fat globules to 139 

— — of ripeners of cream to.. 131, 135 

— — of temperature to 135 

— — of viscosity to 134 

— rise of temperature in 143 

Cistern, milk 5 

Citric acid 25 

Cleaning tinware 82 

— utensils 13 

Cleanliness 81 

Club-house cheese 199 

Cloth strainers 83 

Coagulation 158 

Coccus 65 

Cochran, C. B., mentioned 47 

Cochran's method 47 

Cold storage 230 

Columbia separator 117 

Color fermentations 69 

— of butter 154 

— of cheese 189 

Colostrum 9, 18 

— corpuscles 18 

— test for 18 

Combined butter and cheese fac- 
tories 217 

Commei-cial lactic ferment 124 

Comparison of lactometer scales 232 

— of thermometer scales 231 

Composite sampling 57 

Composition of butter 153 

— of cheese 189 

— of cream 92 

— of milk 17 

Concussion in churning 137 

Condensed milk 226 

Conn culture 126 

— H. W., mentioned 123, 125 

Connective tissue 3 

Constituents of milk 16 



PAGE 

Construction of creameries 213 

Control apparatus, Fjord's 43 

— of fermentations 74 

— of milk supply 90 

Cooking the curd 177 

Coolers, milk 85 

Cornell Univ. Agr. Expt. Station, 

quoted 85, 100, 103, 116-118 

Cornevin, quoted 17 

Correction of lactometer for tem- 
perature 232 

Cooley system 98 

Cooling milk for cheese making 165 

Corpuscles, colostrum 18 

Corrosive sublimate 57 

Cottage cheese 206 

Cows' milk 16 

Cows, number in United States 221 

— official inspection of 88 

Cream 92 

— cheese 192 

Philadelphia 196 

— composition of 92 

— degree of ripeness necessary 128 

— dilution in churning 142 

— effect of different degrees of 

ripeness on clmrning 131 

— estimation of fat by Babcock test 53 

— frothing or swelling 142 

— gathering system 39, 225 

— glasses 34 

— gauges 34 

— over-ripened 132 

— relation of ripeness to churning. 135 

— — of temperature to ripening. .127 

— ripening 121 

— screw 112 

— separation of 92 

— test bottles 52 

— use of starter in ripening 124 

Creameries 209 

— construction of 213 

— gathered cream 225 

— gravity system 21Q 

— ground plan 212 



Index. 



273 



PAGE 

Creameries, location of 209 

— pumping system 211 

— water supply of 214 

Creaming, deep setting 97 

— efficiency of centrifugal 116 

— effects of delayed setting 100 

— — of dilution on 102 

— losses in deep setting 98 

— — in shallow pan 97 

— necessity for 94 

— relation of centrifugal force to. .109 

— — of fat globules to 95 

— — of inflow to complete 110 

— — of solids not fat to 95 

— — of temperature to centrifugal. 110 

— — of viscosity of milk to 96 

— shallow pan 99 

— systems of 93 

— theory of centrifugal 107 

— — of deep setting system 98 

Creamometers 34 

Curd, cutting 175 

— grinding 181 

— heating or cooking 177 

— knives 176 

— in Babcock test 60 

— matting or cheddaring 179 

— mill 181 

— sink 179 

— salting 182 

Curdling, sweet 69 

Cui'ds, fast- working 188 

— floating 187 

— gassy 187 

Curing cheese 1 85 

— rooms, construction of 217 

— — sub-earth duct for 217 

Cutting the curd 175 

Dairy buildings, farm 218 

— laws 239 

the New York 252 

— legislation 227 

— markets 229 

— statistics 222 

Dairying, associated 223 



PAGE 

Danish separator, large 117 

— — small 117 

— Weston separator 117 

Dean, H. H., quoted 87, 161 

Decinormal alkali 129, 233 

Deep setting creaming 97 

— — system 93 

— — — theory of 98 

DeLaval lactocrite 43 

— separator 118 

Delayed setting, effect on creaming. 100 

Detachable neck test bottle 52 

Determination of lactic acid 129, 233 

Development of the factory system. 224 

Dextrose 25 

Difficult churning 141 

Dihition, effect of on creaming 102 

— of cream in churning 142 

Disease germs 69, 78 

— relation of pasteurization to 88 

Diseased herds, official inspection a 

prevention 88 

Disinfectants 76 

Double Gloucester cheese 199 

— necked test bottle 52 

Ducts, milk 3, 5 

Dust, relation of bacteria to 75 

Dutch cheese 206 

Edam cheese 201 

Effect of delayed setting on creaming 100 

— of dilution on creaming 102 

Electricity as a germicide 77 

Electrolysis 77 

Emmenthaler cheese 200 

Emulsion 22, 92 

English Cheddar cheese 199 

— cheese 199 

Essential oils 20 

Estimation of solids not fat 63, 232 

— of total solids 63 

Excrement, animal, relation of bac- 
teria to 75 

Experiment Station bulletins 259 

— Stations, mentioned 44 

Extract, rennet 171 



274 



Index. 



PAGE 

Factories, arrangement of cheese. . .215 

— butter and cheese 209 

— combined butter and cheese 217 

— gathered cream 225 

Factory system, development of 224 

Fahrenheit thermometer 231 

Failyer and Willard, mentioned 45 

Failyer and Willard's method 45 

Farm dairy buildings 218 

Farrington's alkaline tablets... 79 

129, 233 
Farrington, E. H., quoted.. 79, 125, 129 

Fast working cui-ds 188 

Fat as a basis of value for milk in 
cheese making 163 

— globules 22 

— — relation of , to churning 139 

— — size of 95 

— loss of, in cheese-making 1G4 

Fats 19 

— effect of period of lactation on . . 27 

— formation of 8 

— gravimetric determination of 33 

— non volatile 22 

— volatile 20 

Ferment, preparation of artificial. . .234 
Ferments, lactic 124 

— soluble 158 

Fermentations, abnormal 69 

— alcoholic 69 

— butyric 69, 74 

— chromogenic 69 

— control of 74 

— germs of 65 

— lactic 69, 71, 124, 165 

— normal 69 

— of milk 69 

— peptogenic 69, 73 

— poisonous 71 

— putrefactive 69, 73 

— undesirable in cheese making.. .186 

Feser's lactoscope 42 

Fibrin 23, 24 

Filled cheese law 229,246 

Finish of butter 156 



PAGE 

Fission 65 

Fjord's control apparatus 43 

Flavor of butter 154 

— — — relation of wash water to . 147 

— of cheese 189 

Fleischmann, quoted 17 

Fleshy udder 3 

" Flinty break" of cheese 189 

Floating curds '. 187 

Floors, cement 213 

Follicle, ultimate 3, 6 

Food, influence on composition of 

milk 29 

Fore milk and strippings 29 

Formalin 77 

Formation of cheese rind 185 

Formula for solids not fat, Bab- 
cock's 232 

Richmond's 232 

Forage, relation of bactei'ia to 75 

Fright, effect on milk secretion 14 

Frothing of cream 142 

Galactose 25 

Gases in milk 84 

"Gassy" curds 187 

Gathered cream system 225 

Gerber's test 48 

Germ diseases 69 

Germs of disease 78 

— of fermentation 65 

Glasses, cream 34 

Glassware, calibration of Babcock 

test ....235 

Globules, fat 22 

Gloucester cheese, singleland double.199 

Glycerides 22 

Goats' milk 16 

Gorgonzola cheese S!b3 

Gouda cheese 202 

Grain of butter 154 

Gravimetric analysis 33 

Gravity creaming 93, 94 

— system of creamery construction. 210 

Grinding the curd 181 

Gruyere cheese 200 



Index. 



275 



PAGE 

Gauges, cream 34 

Gurler, H, B., quoted 126 

Hansen's lactic ferment 125 

Hard cheeses 191 

Hay, relation of bacteria to 75 

Heating the curd 177 

Heeren's pioscope 41 

Herds, official inspection of diseased. 88 

Holding up milk 5 

Home-trade cheese 192 

Horizontal separators 108 

Hot iron test 235 

Hj-drochloric acid for ripening 

cream 123 

Hydrometer 35 

Imitation Swiss cheese 198 

Indicator, litmus 233 

— phenolphthalein 233 

Infection, prevention of 74 

Inflow, relation of to complete 

creaming 110 

Iowa Station test. 46 

Ironclad tinware 81 

Iron, phosphate of 25 

Jordan, Dr. W. H., quoted 102 

Jumbo separator 118 

Keeping quality, relation of lactic 

acid to 131 

Knives, curd 176 

Pvoenig, quoted 17 

Koumiss 16 

Lactation period, effect on composi- 
tion of milk 26 

Lactic acid 24, 72, 124 

determination of 129, 233 

relation to keeping quality of 

butter 131 

— fermentations 69, 71, 124, 165 

— ferments 124 

Lactobutyrometer 41 

Lactochrome 25 

Lactometer 35 

— comparison of scales 36 

— corrections for temperature. .37, 232 

— Board of Health 231 



PAGE 

Lactometer, Quevenne 232 

— scales, comparison of 232 

Lactocrite 43 

Laetoprotein 26 

Laetoscope 42 

Lactose 24 

Law, dairy 239 

— filled cheese 229, 246 

— oleomargarine 228, 239 

— the New York dairy 252 

" Leaky" cheese 194 

LeFeldt and Lentsch, mentioned ... 106 

Leffman and Beam, mentioned 148 

Legal standards for milk 90, 227, 239 

Legislation, dairy 227 

Lentsch and LeFeldt, mentioned ... 106 

Limburger cheese 196 

Lime, phosphate of 25 

Litmus test 233 

Loss of fat in cheese making 164 

Lymphatics 3 

Magnesia, phosphate of 20 

Males, milk from 10 

Mammse 1 

Mammalia 1 

Mammary gland 1 

Manns, A. G., mentioned 128 

— acid test 128 

Marchand's lactobutyrometer 41 

Mares' milk 16 

Marketing butter 151 

Markets, dairy 229 

Marschall rennet test 168, 234 

Maternity, effect on milk secretion. 9 

Matting 179 

Meadow Sweet cheese 199 

Membrane, formation of, in cheese 

making 177 

Method of Failyer and Willard — 45 

Metric system 237 

Milch Zeitung 117 

Milk, aeration of 84, 166 

— aerators 85 

— albuminoids of 23 

— ash of 25 



276 



Index. 



PAGE 

Milk bacteria 67 

— bitter 69 

— bottles 88 

— cistern 5 

— composition of 17 

— condensed 226 

— constituents 16 

— control of animal over secretion 

of 14 

— coolers 85 

— cooling for cheese making 165 

— defined 1 

— difference in first and last drawn. 29 

— — in night's and morning's 27 

— ducts 3, 5 

— duration of flow 11 

— effect of breed on composition. . . 31 

— — of period of lactation on 26 

— fats 19 

— fermentations of 69 

— from males 10 

— from organs other than the 

mammary gland 10 

— from virgin animals 10 

— gases in 84 

— holding up 5 

— influence of food on composition. 29 
Milking, frequency of 13 

— importance of complete 12 

— — of regularity 13 

— rapidity of 14 

Milk, legal standards for 227, 239 

— over-ripeness for cheese-making. 188 

— paying for, according to percen- 

tage of fat 163 

— quality of, for cheese-making 158 

— relation of \iscosity to churning. 134 

— ripening for cheese making 166 

— ropy ", 69 

— sampler, Scovell's aliquot 58 

— selection for pasteurizing 80 

— secretion 7 

control of animal over 14 

effect of fright on 14 

— of maternity on 9 



PAGE 

Milk secretion, effect of pregnacy 

on 12 

— of sexual excitement on.. 14 

— — relation of blood to 11 

— of nervous organization to. 14 

— — — of parturition to 9 

— skimmed 204 

— slimy 69 

— solids 16 

concerned in making cheese. 157 

— specific gravity of 19 

— sterile 64, 68 

— straining 83 

— sugar 24, 205 

— — formation of 8 

— supply, control of 90 

— tests, Babeock 47 

— — Beimling 48 

— — butyrometer 49 

— — Cochran's 47 

— — Failyer and Willard's 45 

— — Gerber's 48 

— — history 34 

— — Iowa Station 46 

— — Parsons' 4G 

— — Short's 45 

— thief 57, 58 

— viscosity of 96 

Mm, curd 181 

Molds 65 

Monrad, J. H., quoted 197, 200, 207 

Monrad's rennet test 168, 234 

Moore, quoted 126 

Mottled butter 150 

Myristin 22 

Myseost 207 

— alkali 129 

lO 

Nervotis organization, relation to 

milk secretion 15 

Neuf chatel cheese, American 195 

Neiimann, mentioned 58 

New York dairy law 252 

Night's and morning's milk, differ- 
ence in composition 27 

Nipple 2 



Index. 



277 



PAGE 

Nitrate of soda 58 

Non- volatile fats 22 

Normal fermentations 69 

Odor, animal 84 

Official inspection of cows 88 

Ohlsson's test bottle 52 

Oil test churn 40 

Oleic acid 22 

Olein 22 

Oleomargarine 228 

— law 228-239 

Oliver, John 17 

Optimum temperature 66 

Over-ripened cream, bad effects of. .132 
Over-ripe milk in cheese-making. . .188 

Oxidation in cream ripening 123 

Packages, butter 152 

Packing butter 151 

Palmitic acid 22 

Palmitin 22 

Paper coil method, Adams' 34 

— parchment 153 

Parmesan cheese 203 

Parsons, C. L., mentioned 46 

Parsons' method 46 

Parturition, relation of to milk 

secretion 9 

Pasteurization 77, 88 

— apparatus 79 

— selection of milk for 80, 234 

Patrick, Geo. E., mentioned 46 

Paying for milk according to per- 
centage of fat 163 

Peptogenic fermentations 69, 73 

Phenolphthalein 129, 233 

Philadelphia cream cheese 196 

Phosphate of iron 25 

— of lime 25 

— of magnesia 25 

— of potash 25 

Pineapple cheese 195 

Pioscope 41 

Poisonous fermentations 71 

Potash, caustic 58 

— phosphate of 25 



PAGE 

Potassium bichromate 57 

— chloride, 25 

Pot cheese 203 

Preservaline 58 

Preservatives in composite sam- 
pling 57 

Pregnancy, effeot of on milk secre- 
tion 12 

Preparation of artificial starter 234 

Prepared cheese 198 

Press, cheese 184 

Pressed tinware 82 

Pressing cheese 183 

Prevention of infection 74 

Primost 207 

Print butter 153 

Ptomaines 71 

Pumping system of creamery con- 
struction 211 

Putrefactive fermentations 69, 73 

Quality of butter 153 

— of milk for cheese making 158 

legal standards for 90 

Quevenue lactometer 36, 232 

Rancid butter 20 

References 259 

Rennet 158, 170 

— extract 171 

— relation of temperature to ac- 

tivity of 173 

— test . ; 107, 234 

Marschall's 168 

Monrad's 168 

Reports and bulletins of Agr. Expt. 

Stations 259 

Richmond's formula for solids not 

fat 232 

Rind of cheese 190 

— — — formation of 185 

Ripeness, churning cream of differ- 
ent degrees 131 

— of cream, relation to churning.. 135 
Ripening cream 121 

— — amount necessary 128 

relation of temperature to... 127 



278 



Index. 



PAGE 

Ril)ening cream, use of starters in. .124 

— of milk for cheese making 1G6 

Ropy milk C9 

Roquefort cheese 16, 202 

Rules and tests, useful 231 

RusseD, H. L., quoted 79,125 

Russian separator 119 

Rusty tinware 82 

Rutin 20 

Sage cheese 194 

Salt loO 

Salting butter 148 

— cheese 182 

Salicylic acid 77 

Sampler, Scovell aliquot milk..^... 58 
Scale of perfection for butter 157 

— — — for cheese 190 

Sehmierkase 206 

Schweitzer cheese 200 

Scovell aliquot milk sampler 58 

Secretion of milk 7 

Selecting milk for pasteurizing 80 

Separation, theory of centrifugal. . . 107 
Separator, adjustable 117 

— Alexandra Jumbo 118 

— Alpha 118 

— Arnold's 117 

— Columbia 117 

— Danish Weston 117 

— De Laval 118 

— horizontal 108 

— large Danish 117 

— mecha'l contrivances in bowl of .113 

— medium Brown 117 

— Sharpies' Russian 119 

— slime 109 

— small Danish 117 

— system 93 

— United States 119 

— Victoria 117 

Setting, effect of delay on creaming. 100 

— milk for cheese making 173 

Sewers 214 

Sexual excitement, effect of, on 

milk secretion 6 



PAGE 

Shallow pan creaming 96 

— — system 93 

Sharpies' Russian separator 119 

Short, F. G., mentioned 45 

Short's method 45 

Size of fat globules 95 

Single Gloucester cheese 199 

Sink, curd 179 

Skimmed cheese 192, 229 

— milk 204 

— — estimation of fat by Babcock 

test 54 

test bottle 52 

Skimmer 97 

Skimming 97 

Slime, separator 109 

Slimy milk 69 

" Sloppy" cheese 194 

Soda, caustic 58 

Sodium chloride 25 

— nitrate 58 

Soft cheese 191 

Solids concerned in making cheese .157 

— estimation of total 63 

— not fat, estimation of 63, 232 

— — — relation to creaming 95 

— total, determination of 33 

Soluble ferments 158 

Soxhlet's method 43 

Specific gravity 10, 35 

Specks, black, in Babcock test 61 

Speed of bowl, relation of to com- 
plete creaming 38, 110 

Sphincter muscle 4, 5 

Spirillum 65 

Spore ; . . 66 

Standards for milk, legal 90, 227, 239 

" Standing up" quality of butter 122 

Starters 124, 169 

— preparation of 234 

" State Brands" 229 

Statistics, dairy 222 

Stearic acid 22 

Stearin 22 

Sterile milk 64, 68 



Index. 



279 



PAGE 

Sterilization 77 

Stilton cheese 190 

Stirred-curd cheese 192 

Storch, mentioned 12." 

Strainers 81) 

Straining milk 8'J 

Streaked butter 1^0 

Strippings and fore milk 29 

Sub-earth duct for curing-rooms 217 

Sugar of milk 24, 205 

Sulphuric acid 60 

Sunlight, effect on cleanliness 82 

Surface tension 23, 92 

Sweet cream butter 122, 131 

— curdling 69 

Swelling of cream 142 

Swiss cheese 200 

imitation 198 

System, metric 237 

Tablets, Farrington's alkaline. .129, 233 

Teat 2 

Temperature, best for churning 135 

— — for deep setting creaming 98 

— — for shallow pan creaming 96 

— — for washing bvitter 145 

— correction for lactometer 232 

— effect of, on activity of rennet. . .173 

— for ripening cream 127 

— relation of, to centrifugal sep- 

aration 110 

— — of, to churning 135 

— rise of, in churning 143 

Testing Babcock glassware 55 

Tests and rules, useful 231 

Test, Babcock 47 

— — calibration of glassware 235 

— Beimling 48 

— bottle, Babcock 52 

B. and W 52 

cream 52 

— — detachable neck 52 

double-necked 52 

Ohlsson 52 

— — skimmed milk 52 

— butyrometer 49 



PAGE 

Test, chum 39 

— Cochran's 47 

— Failyer and Willard's 45 

— Gerber's 48 

— history of milk 34 

— hot iron 235 

— Iowa Station 46 

— litmus 233 

— Manns' acid 128 

— Parsons' 40 

— pheuolphthalein 233 

— rennet 167, 234 

— Short's 45 

I Texture of butter 122, 134 

— relation of wash-water to. 146 

1 — of cheese 189 

Thermometer, Fahrenheit 231 

— Centigrade 231 

— scales, comparison of 231 

Theory of centrifugal separation.. .107 

Tiemann, mentioned 123 

Tinware, ironclad 81 

— pressed 82 

— rusty 82 

— washing '. 82 

Tissue, connective 3 

Total solids, determination of 33 

— — estimation of 63, 232 

Ti-uckle cheese 195 

Turbine, steam, Babcock 51 

Tubercle bacillus 78 

Tyrotoxicon 71 

Udder 2 

Ultimate follicle 3, 6 

United States separator 119 

— — type of separator 114 

Urea 26 

Useful rules and tests 231 

Utensils, cleaning 75 

Van Slyke, Dr. L. L., mentioned.. 30 

quoted 159,164 

Vermont Agr. Espt. Station, quoted. 103 

Vessels, cleaning 75 

Victoria separator 117 

Virgin animals, milk from 10 



280 



Index. 



PAGE 

Viscosity of milk 92 

— relation of, to churning . . 134 

— — of to creaming 96 

Volatile fats 20 

— — source of 20 

Von Kleuze, mentioned 191 

Washing butter 144 

— tinware 82 

Water supply of creameries 214 

Wells 214 

" Wet" cheese 194 



PAGE 

Whey 204 

— cheese 207 

Wheyn 208 

White specks in butter 132 

Williams, Jesse, mentioned 224 

Wiltshire cheese 199 

Wire strainers, size of 83 

Working butter 147 

Yeasts 65 

Young America cheese * 195 



Edited by Prof. 1,. H. Bailey. 

THE NURSERY-BOOK. 

By L, H. BAILEY, 

Ifew Edition. Thorourhly recast and revised. 

i6 mo. Cloth, $1. 

This little manual has been one of the most popular of all current horti- 
cultural books. It contains no discussions of the theory or physiology of the 
propagation of plants, but it is a simple and practical account of all the ways in 
which plants are multiplied. It has found a wide circulation, both amongst 
nurserymen and amateurs. Many new illustrations have been made for this 
edition, bringing the number of cuts up to over 150. In its revised form, the 
Nursery Book is the most complete propagating manual in the language. 



THE FORCING- BOOK. 

A Manual of the Cultivation of Vegetables in Glass Houses. 
By L. H. BAILEY, 

16 mo. Cloth, $1. 

This is a handbook of instructions upon the forcing of vegetables for mar- 
ket, and is the completest work of the kind yet published in this country. 

It is based on years of careful experimentation at the Cornell University 
Station, and a long familiarity with the forcing business as practiced in many 
parts of the country. 

It contains full estimates of the cost of heating forcing houses, and of the 
labor necessary to run them. There is also an illustrated chapter on the con- 
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IN PREPARATION. 

THE PRUNING-BOOK. 

By L. H. BAILEY, 

It is strange that the one subject upon which horticulturists have always 
asked the most questions should be wholly without a treatise. The subject of 
pruning is so vitally connected with every horticultural occupation, and the 
questions which it presents are so numerous and so difficult of answer, that 
nothing less than an entire volume can ever set people right in respect to it. 
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approaching readinesss for publication. The work will comprise the culture 
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trees and bushes, and it is expected to be on sale early in 1897. 



Tte Hural SciBUCB S>txus. 

Edited by Prof. 1,. H. Bailey. 

THE SOIL. 

ITS NATXTRE, RELATIONS, AND FUNDAMENTAL PRINCIPLES OF MANAGEMENT. 

By FRANKLIN H. KING, 

Professor of Agricultural Physics, University of IVisconsin. 
i6mo. Cloth. 303 pages. Price, 75 cts. 



CONTEITTS : Introduction. — Sunshine and its Work, The Atmosphere and its 
Work, Water and its Work, Living Forms and their Work, Over and Over 
Again ; The Nature, Functions, Origin, and Wasting of Soils ; Texture, 
Composition, and Kinds of Soil ; Nitrogen of the Soil ; Capillarity, Solution, 
Diffusion, and Osmosis ; Soil Water ; Conservation of Soil Moisture ; Dis- 
tribution of Roots in the Soil ; Soil Temperature ; Relation of Air to Soil ; 
Farm Drainage ; Irrigation ; Physical Effects of Tillage and Fertilizers. 

COMMENTS. 

" I consider it a most desirable addition to our agricultural literature, and a 
distinct advance over previous treatises on the same subject, not only for 
popular use, but also for students and specialists, who w^ill find many new and 
useful suggestions therein." E. W. Hilgard, 

Director of Agricultural Experiment Station, Berkeley, Cal. 



THE SPRAYING OF PLANTS. 

By E. G. LODEMAN, 

Instructor in Horticulture in Cornell University. 
i6ino. Cloth. 399 pages. Price, $1.00. 



CONTENTS. 

Part I. The History and Principles of the Spraying of Plants. 
Part II. Specific Directions for the Spraying of Cultivated Plants. 

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well, which should be in the hands of every farmer, gardener and fruit-grower. 
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B. C. BUFFUM, 

The University of Wyoming Agricultural College, Laramie, Wyo. 
" This is a book for every gardener and every one who has a garden, for 
every fruit-grower and eveiy farmer. The necessity of spraying for a great 
variety of garden, field, and fruit crops is now so generally recognized^ that a 
manual on the subject has become a necessity. The destruction of injurious 
insects and fungi occupies an important place in the operations of gardeners, 
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which the subject is treated in this volume is highly creditable to the author, 
and commends it to the attention of every cultivator."— Vick.''s Monthly. 



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The HORTICULTURIST'S Rule-book. 

A COMPENDIUM OF USEFUL INFORMATION FOR FRUIT-GROWERS, TRUCK- 
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Third Edition, Thoroagflilj Revised and Recast, with Many Additions. 
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Among the additions to the volume in the present edition are: A chapter 
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PLANT-BREEDING. 

By L. H. BAILEY. 

i6mo. 293 pages. Cloth, Limp, $1.00. 

Vnifortn with " The Horticulturist^ s Rule-Book. 



CONTENTS 

The Fact and Philosophy of Variation. Borrowed Opinions, of B. Verlot, E. 
The Philosophy of the Crossing of A. Carri^re, and W. O. Focke, on 

Plants. Plant-Breeding. 

Specific Means by which Garden Detailed Directions for the Crossing 

Varieties originate. of Plants. 

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IN THE PRESS. 

THE APPLE. 

By L. H, BAILEY. 

The work is to comprise two parts — the first treating of all the practical 
matters of apple-growing, and the second of such scientific matters as the 
botany of the apple, its history and evolution, production of new varieties, 
and the like. It is expected that the work will be completed and ready for 
publication in the fall. 

MILK AND ITS PRODUCTS. 

By H. H. WING. 



THE FERTILITY OF THE LAND. 

By I. P. ROBERTS. 



Other volumes in the series to follow are : 
Physiologfy of Plants. By J. C. Arthur, of Purdue University. 
Grasses. By W. H. Brkwkr, of Yale University. 
Bush Fruits. By F. W. Card, of University of Nebraska. 

Plant Diseases. By B. T. Gai,i.oway, E. F. Smith, and A. F. 
Woods, of the United States Department of Agriculture. 

Seeds and Seed Growing^. By G. H. Hicks, of the United States 

Department of Agriculture. 
Legfuminous Plants. By E. W. Hilgard, of the University of 

California. 
Feeding: of Animals. By W. H. Jordan, of Maine Experiment 

Station. 
Irrigfation. By F. H. King, of the University of Wisconsin. 



W PREPARATION. 

EVOLUTION OF OUR NATIVE FRUITS. 

By L. H. BAILEY. 



THE MACMILLAN COMPANY. 

66 Fifth Avenue, NEW YORK. 









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HECKMAN 

BINDERY INC. 

,_Jl^ N. MANCHESTER, 
^^^^ INDIANA 46962 



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